ISSN 0024-5135 LIVARSKI VESTNIK 69/2022 3 DRUŠTVO LIVARJEV SLOVENIJE SLOVENIAN FOUNDRYMEN SOCIETY LIVARSKI VESTNIK Izdajatelj / Publisher: Društvo livarjev Slovenije Lepi pot 6, P.P. 424, SI-1001 Ljubljana Tel.: + 386 1 252 24 88 E-mail: drustvo.livarjev@siol.net Spletna stran: www.drustvo-livarjev.si Glavni in odgovorni urednik / Chief and responsible editor: prof. dr. Alojz Križman E-mail: probatus@triera.net Tehnicno urejanje / Technical editoring: mag. Mirjam Jan-Blažic Uredniški odbor / Editorial board: prof. dr. Alojz Križman, Univerza v Mariboru prof. dr. Primož Mrvar, Univerza v Ljubljani prof. dr. Jožef Medved, Univerza v Ljubljani prof. dr. Rebeka Rudolf, Univerza v Mariboru prof. dr. Andreas Buhrig-Polaczek, Giesserei Institut RWTH Aachen prof. dr. Peter Schumacher, Montanuniversität Leoben prof. dr. Rüdiger Bähr, Otto-von Güricke-Universität Magdeburg prof. dr. Reinhard Döpp, TU Clausthal prof. dr. Jerzy Józef Sobczak, Foundry Research Institute, Krakow prof. dr. Jaromir Roucka, Institut Brno prof. dr. Branko Bauer, Univerza v Zagrebu Prevod v angleški jezik / Translation into English: Marvelingua, Aljaž Senicar s.p. Lektorji / Lectors: Angleški jezik / English: Yvonne Rosteck, Düsseldorf Slovenski jezik / Slovene: Marvelingua, Aljaž Senicar s.p. Tisk / Print: Fleks d.o.o. Naklada / Circulation: 4 številke na leto / issues per year 800 izvodov / copies Letna narocnina: 35 EUR z DDV Year subscription: 35 EUR (included PP) Dano v tisk: september 2022 Bentoproduct d.o.o. Stepe Stepanovica 181c BiH-78000 Banja Luka T: +387 51 225 214 E: lidija.dangubic@bentoproduct.ba www.bentoproduct.ba VSEBINA / CONTENTS Stran / Page: B. Dickinson, T. Midea, A. Adams: Ocenjevanje dizajnov železnih filtrirnih plošc SEDEX* – 30 let pozneje / Evaluating SEDEX* Iron Filter Print Designs – 30 Years Later 134 S. K. Subbarayalu, M. Manapuram: Oblikovanje in izdelava ulitka bata motorja indijskega lahkega motornega vozila s postopkom tridimenzionalnega tiska: študija / Design and Manufacture of Engine Piston Casting of Indian Light Motor Vehicle by Three-Dimensional Printing Process: A Study 153 J. Brence, S. Kastelic, A. Mahmutovic, P. Mrvar: Optimizacija ulivno-napajalnega sistema ulitka kape izolatorja iz bele temprane litine / Design Optimization of Gating System for Insulator Cap from White-Heart Malleable Iron 170 AKTUALNO / CURRENT 62nd IFC in Portoroz - Slovenia 30 years membership in WFO 182 Društvo livarjev Slovenije ima novega castnega clana 186 63. IFC PORTOROŽ 2023 187 Galerija slik vseh sponzorjev-razstavljavcev na 62. IFC Portorož 2022 188 Galerija slik vseh razstavljavcev na 62. IFC Portorož 2022 190 Pregled livarskih prireditev v letu 2022 / 2023 191 Pokrovitelji 62. IFC Portorož 2022 192 Livarski vestnik je vpisan v razvid medijev Ministrstva za kulturo pod zaporedno številko 588 B. Dickinson, T. Midea, A. Adams Livarski vestnik, letnik 69, št. 3/2022 Vesuvius Inc. (Cleveland Foundry), USA / ZDA Ocenjevanje dizajnov železnih filtrirnih plošc SEDEX* – 30 let pozneje Evaluating SEDEX* Iron Filter Print Designs – 30 Years Later Uvod Ta uvodni prispevek se osredotoca na analizo in vrednotenje vec konceptov oblikovanja filtrirne plošce z uporabo programske opreme za simulacijo procesa litja, ki uporablja sofisticirane modele prvega nacela za analizo toka tekocine. Cilj tega dela je raziskati težave, s katerimi se srecujejo v livarnah, in povecati koristi filtracije za dovajanje taljene kovine najboljše možne kakovosti v votlino forme, kar zgotavlja proizvodnjo visokokakovostnih ulitkov. Analiza temelji na industrijskih standardih zasnove filtrirnih plošc, ki predstavljajo osnovo za primerjave pretoka tekocine, rezultate pa smo primerjali z zasnovami filtrirnih plošc, ki smo jih spremenili z namenom izboljšanja izkoristka. V industriji ustaljene filtrirne plošce so opredeljene kot filtrirne plošce, zasnovane med uvodnim razvojem filtrov za železne ulitke. Nekatere kljucne zahteve za optimalne rezultate so bile identificirane med razvojem, vkljucno z naslednjimi.1–4, 6–11 • Povecanje izpostavljenosti vhodne strani filtra, da bi zagotovili najvecji skupni pretok. • Povecanje podpore (na štirih straneh), da bi zagotovili, da inercijske sile na filter zaradi toka železa ne presežejo trdnosti filtra. • Zmanjšanje verjetnosti, da bi železo potovalo okoli filtra (in ne skozi njega), in sicer z oblikovanjem podporne strani na izhodu filtrirne plošce, ki se ujema s tolerancnimi dimenzijami filtra. 1 Introduction This initial work focuses on the analysis and evaluation of several filter print design concepts using casting process simulation software employing sophisticated, first principal fluid flow analysis models. The goal of this work is to investigate problems experienced in foundries and maximise the benefits of filtration to deliver the best possible quality molten metal to the mould cavity, thereby producing high-quality castings. The analysis uses industry standard filter print designs as the baseline for the fluid flow comparisons and compares these results to filter print designs that have been altered for yield improvement. Industry standard filter prints are defined as those designed during the initial filter development for iron castings. Some of the key requirements for optimal results were identified during the development, including thefollowing.1-4,6-11 • Maximise exposure of the filter inlet face to ensuremaximum total flow • Maximise (four-sided) support to ensure that the inertial forces on the filter from the iron flow do notsurpass the strength of the filter • Minimise the possibility of iron passing around (not through) the filter by designing the support ledge on the filter print outlet to match filter tolerance dimensions • Minimise turbulence by designing the filter print volumes such that the flow smoothly transitions from inlet to outlet • Zmanjšanje turbulence z oblikovanjem filtrirnih plošc s takšno prostornino, da pretok neovirano prehaja od vhoda do izhoda. Kombinacije teh znacilnosti so se uporabile za opredelitev temeljev za standarde oblikovanja filtrirnih plošc. V zadnjih 30 letih so te zasnove neprekinjeno preskušali, skozi uporabo in med ocenjevanjem v livarnah pa so se rahlo izboljšale. Prve simulacije, izvedene v tej študiji, so bile uporabljene za oceno teh standardnih modelov. Izboljšanje izkoristka je velika prednostna naloga vseh livarn, dovajalni sistemi kakor tudi vsi drugi postopki litja pa se zaradi zmanjšanja teže skrbno analizirajo. Vcasih se za zmanjšanje teže izvedejo spremembe standardnih filtrirnih plošc brez podrobne analize ucinka na lastnosti pretoka tekocine dovajalnega sistema. Spremembe, ki negativno vplivajo na pretok tekocine kovine vodijo v povecanje turbulence, neenakomeren pretok in zmanj­šano ucinkovitost filtriranja. V tej študiji je bilo ovrednotenih tudi vec takšnih situacij. Rezultati tega prispevka obsegajo vec idej o tem, kako najbolje oblikovati filtrirne plošce in razdelilne sisteme, ki so uporabni za vse pripomocke za filtriranje železa. Analitska metoda Kot izhodišce za zacetek analize smo izbrali standardne kvadratne vodoravne in navpicne filtrirne plošce 75 mm x 75 mm x 22 mm (2,95 x 2,95 x 0,866 palca). Na obeh vrstah filtrirnih plošc smo izvedli vec modifikacij, da bi ocenili ucinek takšnih sprememb zasnove na dinamiko tekocin. Vse analize pretoka tekocine smo izvedli z uporabo programske opreme These combined characteristics were used to define the basis for standard filter print design. Over the past 30 years, these designs have been continually tested and have slightly evolved through applications and foundry evaluations. The first simulations conducted in this study were used to evaluate these standard designs. Yield improvement is a high priority for all foundries, and gating systems are analysed as carefully as all other aspects of the casting process to reduce weight. Alterations are sometimes made to standard filter prints to reduce weight without careful analysis of the effect on the fluid flow properties on the gating system. Changes that adversely affect molten metal fluid flow can result in increased turbulence, non-uniform flow, and areduction in filtration efficiency. Several of these situations were also evaluated in this study. The results of this work include several ideas on how to best design filter prints and runner systems that applyto all iron filtration devices. 2 Method of Analysis Standard 75 mm x 75 mm x 22 mm (2.95 x 2.95 x 0.866 inch) thick square horizontal and vertical filter prints were chosen as the baseline to begin the analysis. Several modifications were made to both types of filter prints to evaluate the effect of these design modifications on fluid dynamics. All fluid flow analyses were conducted using MAGMA5 (Version 5.3.0.4) with Solver 5. The mesh size for all simulations was approximately 10 million elements (700,000 metal cells). The metal dataset represents ASTM A536-84 (80-55-06/GGG­ 60) grade ductile iron poured at 1400°C (2552°F) into a sand mould. The plate casting is approximately 305x610x76mm (12x24x3in) MAGMA5 (razlicica 5.3.0.4) z dodatkom Solver 5. Velikost mreže za vse simulacije je bila približno 10 milijonov elementov (700.000 kovinskih celic). Nabor podatkov o kovini predstavlja siva litina razreda ASTM A536-84 (80-55-06/GGG-60), v pešceno formo ulita pri temperaturi 1.400 °C (2.552 °F). Ulitek plošce ima dimenzijo pribl. 305 x 610 x 76 mm (12 x 24 x 3 in) in tehta približno 100 kg (220 lb). Skupna teža med litjem je bila približno 110 kg (242 lb). Filter smo ponazorili s standardnimi podatki o padcu tlaka med filtracijo s peno 10 ppi v primeru 22 mm (0,866 palca) debelega filtra SEDEX5. V vseh primerih se je program izvajal s funkcijo »Samodejni nadzor polnjenja«. Program je bil za vse simulacije prisiljen vzdrževati višino taline v livarskem lijaku na 70 %, s cimer so bili zagotovljeni enako pogoji litja v vseh simuliranih razlicicah. Cas polnjenja je bil za vse konfiguracije približno 24 sekund, kar predstavlja hitrost pretoka približno 4,5 kg/s (10 lb/s). Zasnove dovajalnega sistema, ocenjene v tem porocilu, so reprezentativne za tiste dovajalne sisteme, ki se uporabljajo v industrijskih standardih, pri visokem tlaku, s svežim peskom ter z avtomatizirano opremo za formanje. Obmocje dušenja je bilo izracunano na podlagi Enacbe 1. W A = Enacba (1) tDC v2gH Vrh lijaka smo izracunali z Enacbo 2. PL PL AVrh lijaka = Vx AEnacba (2) VST Lijak ima zožitev pod kotom treh stopinj, ki omogoca odstranjevanje forme. Sistem dovodnega kanala temelji na razmerju lijak:razdelilni kanal:dovodni kanal 1,0:1, 1:1,2 in dimension and approximately 100 kg (220 lb) in weight. The totalpour weight was approximately 110kg (242lb). The filter was represented using standard 10ppi, foam filtration pressure drop data for a 22mm (0.866in) thick SEDEX filter5. In all cases, the program was run using the “Automatic Filling Control” feature. Specifically, the program was forced to maintain a pouring cup metal height of 70% for all the simulations, thus ensuring identical pouring conditions for all versions simulated. Fill time was approximately 24 seconds for all configurations, representing a flow rate of approximately 4.5kg/s (10lb/s). The gating designs evaluated in this report are representative of those in use on industry standards, highpressure, green sand, automated moulding equipment. The choke area was calculated using Equation 1. W A = Eqn. (1) tDC v2gH The top of the sprue was calculated using Equation 2. VPL x APL ASprue Top = Eqn. (2) VST The sprue was tapered at a three- degree angle to allow for mould stripping. The runner system follows a ratio of Sprue: Runner: Ingate of 1.0:1.1:1.2 The baseline vertical filter print configuration is shown inFigure 1. All simulations were conducted on a Dell Precision 7810 Tower workstation utilising 8 cores. CPU time for each simulation was approximately 10 hours. The baseline horizontal filter print configuration is shown in Figure 2. Slika 1. Standardna navpicna filtrirna plošca Figure 1. Standard vertical filter print Osnovna navpicna konfiguracija filtrirne plošce je prikazana na Sliki 1. Vse simulacije smo izvedli na delovni postaji Dell Precision 7810 Tower z uporabo 8 jeder. Cas CPE za vsako simulacijo je bil približno 10 ur. Osnovna vodoravna konfiguracija filtrirne plošce je prikazana na Sliki 2. Rezultati in razprava Vsi prikazani rezultati pretoka tekocine so analiticni in temeljijo na enacbah pretoka Navier-Stokes. Napovedi pretoka iz tega prvega glavnega pristopa dinamike tekocin so vec desetletij potrjevali v številnih industrijah in aplikacijah, med drugim tudi v povezavi s talIno. Pricakuje se, da bodo prikazani primerjalni rezultati zelo pomenljivi in natancni. Vendar pa bodo v prihodnjem delu izvedeni livarski preskusi za nadaljnjo Slika 2. Standardna vodoravna filtrirna plošca Figure 2. Standard horizontal filter print 3 Results and Discussion All fluid flow results shown are analytical and based on the Navier-Stokes flow equations. Flow predictions from this first principal fluid dynamic approach have been validated for several decades in many industries and applications, including molten metal applications. The expectation is that the comparative results shown should be very meaningful and accurate. However, foundry trials will be conducted in future work to further validate the conclusions presented in this paper. 4 Vertical Filter Print Example The flow characteristics for a standard vertical filter print are shown in Figure 3. The colors represent flow velocities. At 10% filled, the flow is a steady state in and around the filter print. The color scale Slika 3. Precni prerez sredinske crte dovajalnega sistema standardne navpicne filtrirne plošce, hitrost pretoka sistema pri napolnjenosti 10 % Figure 3. Centerline cross-section of standard vertical filter print gating system flow velocity at 10% filled potrditev zakljuckov, predstavljenih v tem prispevku. Primer navpicne filtrirne plošce Znacilnosti pretoka za standardno navpicno filtrirno plošco so prikazane na Sliki 3. Barve predstavljajo hitrost pretoka. Pri napolnjenosti 10 % je pretok v filtrirni plošci in okoli nje enakomeren. Barvna lestvica sega od svetlo modre (nizka hitrost, blizu 0,2 m/s (0,66 ft/s) do bele (višja hitrost, blizu 2,0 m/s (6,6 ft/s). Pretok skozi filter je približno 0,3–0,4 m/s (1-1,3 ft/s), pretok pred filtrom pa je laminaren in zajema celoten filter. Pretok za filtrom je enakomeren in stabilen. Precni prerez skozi sredino filtrirne plošce v istem casovnem koraku prikazuje hitrost tekocine in vektorje pretoka (Slika 4). Ta slika jasno prikazuje enakomeren pretok in izkoristek celotne površine filtra za nadzor pretoka in filtracijo. Takšen sistem filtrirne plošce in dovajalnega sistema je Slika 4. Precni prerez sredinske crte standardne navpicne filtrirne plošce, hitrost pretoka pri napolnjenosti 10 % Figure 4. Centerline cross-section of standard vertical filter print flow velocity at 10% filled goes from light blue (low velocity, near 0.2m/s (0.66 ft/s) to white (higher velocity, near 2.0 m/s (6.6 ft/s). Flow through the filter is approximately 0.3-0.4 m/s (1-1.3 ft/s), and the flow before the filter is laminar and covers the entire filter. Flow after the filter is uniform and stable. A cross-section through the middle of the filter print at this same time step shows the fluid velocity and flow vectors (Figure 4). This image clearly shows the uniform flow, and the utilisation of the entire filter face for both flow control and filtration. This can be considered a well-designed filter print and gating system and will serve as a baseline for this vertical filter print section of this study. In application, extreme changes have sometimes been made to standard filter prints to save weight, increase yield, and/or fit within pattern plate restrictions. Figure 5 shows one actual example. While this design results in a 35% weight reduction in the filter print design (0.9kgs, 2lbs), the flow characteristics in the dobro zasnovan in bo služil kot osnova za ta odsek navpicne filtrirne plošce v tej študiji. V praksi se vcasih za prihranek pri teži, povecanje izkoristka in/ali izpolnjevanje omejitev vzorcne plošce uporabljajo skrajne spremembe standardnih filtrirnih plošc. Slika 5 prikazuje primer iz prakse. Ta zasnova omogoca 35-odstotno zmanjšanje teže zasnove filtrirne plošce (0,9 kg, 2 lb), vendar pa ima negativen vpliv na lastnosti pretoka v filtrirni plošci in dovajalnem sistemu. Slika 6 prikazuje znacilnosti pretoka na središcni crti filtrirne plošce in dovajalnega sistema pri napolnjenosti 6,5 %. (Opomba: rezultati za vse dizajne se primerjajo z rezultati standardnih oblik filtrirnih plošc. Standardni rezultati so prikazani na spodnjih slikah v primerjalnih podobah za primere navpicne filtrirne plošce.) Zaradi ostrih kotov spremenjene vhodne odprtine filtrirne plošce se tok pospeši proti središcu vhodne odprtine filtra in se zacne nato premikati skozi filter, preden popolnoma napolni obmocje vhodne odprtine filtrirne plošce. Znacilnosti pretoka za standardno zasnovo filtrirne plošce so povezane z bolj enakomerno porazdeljenim filter print and gating system are adversely affected. Figure 6 shows the flow characteristics at the centerline of the filter print and gating system at 6.5% filled. (Note: The results for all designs are compared to the standard filter print design results. The standard results are shown as the bottom image in the comparative figures for the vertical filter print examples.) Because of the sharp angles of the modified filter print inlet, the flow accelerates into the center of the filter inlet face and begins to move through the filter before completely filling up the filter print inlet area. The flow characteristics for the standard filter print design show a more evenly distributed flow pattern within the filter print inlet and at the filter inlet face. The high filter inlet faces velocities of the reduced filter print inlet area design results in some very high filter exit face velocities, as shown in Figure 7. Ideally, the filter should reduce flow energy and turbulence by acting as a flow discontinuity. However, this effect is pretokom znotraj vhodne odprtine filtrirne plošce kot tudi na njeni vhodni površini. Visoke hitrosti pri vhodni površini filtra v primeru zmanjšane zasnove vhodne površine filtrirne plošce povzrocijo zelo visoke hitrosti pri izhodni površini filtra, kot je prikazano na Sliki 7. V popolnem primeru bi moral filter zmanjšati energijo toka in turbulenco tako, da deluje kot diskontinuiteta toka. Vendar je ta ucinek zmanjšan, kadar se uporablja zgolj majhna površina filtra. To je jasno prikazano na Sliki 7, kjer je s filtrirno plošco z zmanjšano površino povezan tok, ki izstopa iz filtra z visoko hitrostjo, medtem mitigated if only a small area of the filter is being utilized. This is shown clearly in Figure 7, with the reduced area filter print showing flow exiting the filter at high velocity, while the standard design shows the entire filter filled with metal at very low velocity, and minimal metal flow exiting the filter itself at this time step. In Figure 8, this continues to be the case even at steady state flow. Even at a steady state, the reduced area filter print design is not allowing the entire filter print inlet area to be used and instead is pushing the metal through the center of the filter. This results in the non-uniform ko se pri standardni zasnovi celoten filter s kovino napolni pri zelo nizki hitrosti, iz filtra pa v tem koraku izhaja minimalni tok kovine. Na Sliki 8 se to nadaljuje tudi v primeru enakomernega pretoka. Tudi v stabilnem stanju zasnova filtrirne plošce z zmanjšano površino ne dovoljuje uporabe celotnega vhodnega obmocja filtrirne plošce, temvec se kovina potiska skozi sredino filtra. Posledica je neenakomeren pretok za filtrom in možnost turbulence. To primerjamo s profilom enotnega pretoka pri standardni zasnovi filtrirne plošce, zlasti na izhodni strani filtra, izhodni odprtini filtrirne plošce in navzdol v razdelilnem kanalu. Prav tako zaradi strmega naklona izhodne odprtine filtrirne plošce tok poteka navzgor, kar negativno vpliva na stabilnost flow behind the filter, and the potential for turbulence. Contrast this with the uniform flow profile shown for the standard filter print design, particularly at the filter outlet face, the filter print outlet, and downstream in the runner. Also, due to the steep angle of the filter print outlet, the flow is launched upward, thus adversely influencing the stability of the flow downstream. This can be seen more clearly in Figure 9. Figure 9 shows a top view of a cross-section taken near the bottom of the runner bar, just after the filter print. For the reduced toka v smeri navzdol. To je jasneje razvidno na Sliki 9. Slika 9 prikazuje posnetek pticje perspektive precnega prereza, posnet blizu dna dovodnega kanala neposredno za filtrirno plošco. Pri zasnovi filtrirne plošce z zmanjšano površino je treba upoštevati, da se tok na obeh straneh razdelilnega kanala premika zelo pocasi, in kar je najpomembneje, da se vrtinci v nasprotni smeri predvidenega toka. Potisk kovinskega toka v smeri navzgor zaradi ostrega kota je ustvaril velik in neugoden vrtincni tok, ki tok pocasi potiska nazaj. Ta položaj obstaja je primeren za spodnjo tretjino tega razdelilnega kanala. Standardna zasnova filtrirne plošce prikazuje obmocje pocasnega toka blizu dna razdelilnega kanala na eni strani, vendar so znacilnosti primarnega toka veliko enotnejše z vidika hitrosti in smeri. Slika 10 prikazuje pogled s strani na razdelilni kanal v istem casovnem koraku in kaže jasno razliko med obema oblikama, pri cemer zagotavlja standardna filtrirna plošca enakomernejši, bolje nadzorovan pretok kovine v ulitek. Figure 11. Vertical filter print with filter print inlet area significantly reduced Zmanjšanje površine filtrirne plošce na ta nacin zagotavlja majhno povecanje izkoristka (0,9 kg oz. 2 funta prihranka) ima znatne škodljive ucinke na lastnosti pretoka v vhodni odprtini filtrirne plošce, vhodni area filter print design, note that the flow at both sides of the runner bar is moving very slowly, and most importantly, in the opposite direction of the intended flow. The upward thrust of the metal flow due to the steep angle has created a large, adverse eddy current driving the flow slowly backward. This situation exists for the bottom third of this runner bar. The standard filter print design shows an area of slow flow near the bottom of the runner on one side, but the primary flow characteristics are much more uniform in velocity and direction. Figure 10 shows a side view of the runner bar at the same time step, and shows a clear difference between the two designs, with the standard filter print providing more uniform, controlled metal flow to the casting. Reducing the area of the filter print in this fashion to slightly increase yield (0.9kg, 2lbs saved) has significant adverse effects on the flow characteristics in the filter print inlet, the filter inlet face, the filter outlet face, the filter print outlet, and in the downstream runner bar. This type of alteration is not recommended for best practice filter print design. Figure 11 shows a configuration with the area of the filter print outlet modified to match the standard print shown in Figure 1, but the reduced filter print inlet area is unchanged. In this case, the issues in the filter print inlet area and at the filter inlet face remain the same as discussed previously, but the flow after the filter shows clear improvement. In Figure 12, note how similar the filter outlet face and filter print outlet flow profiles appear when comparing the reduced filter print inlet area configuration with the standard filter print. The main difference between this configuration and the standard filter print is the dramatically higher flow velocities at the filter inlet face for the reduced area design Slika 12. Primerjava pretoka za navpicno filtrirno plošco z mocno zmanjšano vhodno površino filtrirne plošce, napolnjenost 10,0 % Figure 12. Flow comparison for vertical filter print with filter print inlet area significantly reduced at 10.0% filled Figure 13. Vertical filter print with filter print outlet area significantly reduced površini filtra, izhodni površini filtra, izhodni odprtini filtrirne plošce in v spodnjem razdelilnem kanalu. Ta vrsta spremembe za najboljšo prakso oblikovanja filtrirne plošce ni priporocljiva. and the fact that only a small portion of the filter is being used. This is the same situation discussed in the previous configuration, but the yield argument is even more clear this time. Reducing the area of the filter print inlet only saves 0.6kg (1.3lb), but adversely affects the flow such that the entire filter area is not being used to efficiently filter inclusions from the metal. Again, this small yield improvement has a significant adverse effect on the flow and is not recommended in practice. Figure 13 shows a similar design with the area reduced at the filter print outlet only. Reducing the area of the filter print outlet only will save just 0.3kg (0.66lb), and result in very poor flow exitingthe filter print. The flow comparison is shown in Figure 14. In this case, the flow in the filter print inlet and at the filter inlet face has the same beneficial characteristics as that of the standard filter print. However, the flow at the filter outlet face, within the filter print outlet, and in the downstream runner, bar exhibits all of the same poor characteristics shown in Figures 7-10. A filter print design that adversely affects the flow characteristics and delivers minimal yield improvement should not be considered practical. 5 Vertical Filter Print with Slag Trap Example Figure 15 shows the standard configuration with an addition of a slag trap before the filter. This change only adds approximately 0.23kgs (0.5lbs) to the filter print design but results in a positive impact on the overall flow characteristics of the filter print itself. The filter print with a properly designed slag trap displays all of the high-quality flow characteristics shown in the standard Figure 14. Flow comparison for vertical filter print with filter print outlet area significantly reduced at 10.0% filled Slika 11 prikazuje konfiguracijo s spremenjeno površino izhodne odprtine filtrirne plošce, ki je enaka standardni plošci, prikazani na Sliki 1, vendar je zmanjšana vhodna površina filtrirne plošce nespremenjena. V tem primeru se ohranijo težave v površini vhodne odprtine pri filtrirni plošci in na sprednji strani vhodne odprtine filtra, kot je že bilo omenjeno, vendar pa se tok za filtrom ocitno izboljša. Na Sliki 12 je mogoce opaziti, kako zelo podobni so profili toka izhodne odprtine filtra in izhodne odprtine filtrirne plošce, ce primerjamo konfiguracijo zmanjšane vhodne površine filtrirne plošce s standardno filtrirno plošco. Slika 15. Standardna navpicna filtrirna plošca z lovilnikom žlindre Figure 15. Standard vertical filter print with slag trap filter print, with the added benefit of better filter print inlet flow and potentially better filtration efficiency. Figure 16 shows how the trap begins to work as soon as the metal reaches the filter. Glavna razlika med to konfiguracijo in standardno filtrirno plošco je bistveno višja hitrost pretoka na vhodni površini filtra pri zasnovi z zmanjšano površino in dejstvo, da se uporablja zgolj majhen del filtra. Gre za enako situacijo, o kateri smo razpravljali pri prejšnji konfiguraciji, vendar je argument izkoristka tokrat še bolj ociten. Zmanjšanje površine vhodne odprtine filtrirne plošce prihrani samo 0,6 kg (1,3 lb), vendar negativno vpliva na pretok, tako da se celotno obmocje filtra ne uporablja za ucinkovito filtriranje vkljuckov iz kovine. Tudi to majhno izboljšanje izkoristka ima znaten škodljiv ucinek na pretok in se v praksi ne priporoca. Slika 13 prikazuje podobno zasnovo z zmanjšano površino samo na izhodu filtrirne plošce. Z zmanjšanjem površine samo izhodne odprtine filtrirne plošce se prihrani zgolj 0,3 kg (0,66 lb), pretok pri izhodu iz filtrirne plošce pa se mocno poslabša. Primerjava pretoka je prikazana na Sliki 14. V tem primeru ima pretok v vhodni odprtini filtrirne plošce in na vhodni strani filtra enako ugodne lastnosti kot pri standardni filtrirni plošci. Vendar ima tok na izhodni strani filtra znotraj izhodne odprtine filtrirne plošce in v spodnjem razdelilnem kanalu enake negativne lastnosti, kot so prikazane na Slikah 7–10. Zasnova filtrirne plošce, ki negativno vpliva na znacilnosti pretoka in zagotavlja minimalno izboljšanje izkoristka, ne velja za prakticno. Primer navpicne filtrirne plošce z lovilnikom žlindre Slika 15 prikazuje standardno konfiguracijo z vkljucitvijo lovilnika žlindre pred filtrom. Ta sprememba doda zasnovi filtrirne plošce samo približno 0,23 kg (0,5 lb), vendar je njena posledica pozitiven vpliv Note that the bottom of the filter print inlet has filled quickly and that the flow is washing the filter inlet face and moving upwards into the slag trap area. At 8.5% (Figure 17), the flow is nearly stabilised, and the slag trap is forcing the initial metal into a beneficial counter­clockwise eddy current, thus potentially allowing inclusions to reverse direction and slowly float upward into the trap. The standard filter print without the slag trap also has a small area of beneficial eddy currents at the top of the filter print inlet, but very little space to trap and retain inclusions. By 9% filled (Figure 18), the filter print is fully flooded, including the slag trap. na splošne lastnosti pretoka same filtrirne plošce. Filtrirna plošca s pravilno oblikovanim lovilnikom žlindre prikazuje vse lastnosti visokokakovostnega pretoka, kot so There are still some small beneficial eddy currents in the trap. By 10% filled (Figure 19), the filter print is fully stabilised and any inclusions that entered the slag trap will remain. znacilne za standardne filtrirne plošce, z dodatno prednostjo boljšega vhodnega pretoka filtrirne plošce in potencialno ucinkovitejše filtracije. Slika 16 prikazuje, kako lovilnik zacne delovati v trenutku, ko kovina doseže filter. Pomnite, da se je dno vhodne površine filtrirne plošce napolnilo hitro in da tok izpira vhodno površino filtra in se premika navzgor v obmocje lovilnika žlindre. Pri napolnjenosti 8,5 % (Slika 17) je tok skoraj stabiliziran in lovilnik žlindre prisili zacetno kovino v ugoden vrtincni tok v nasprotni smeri urinega kazalca, kar potencialno omogoca vkljuckom, da spremenijo smer in pocasi lebdijo navzgor v lovilnik. Standardna filtrirna plošca brez lovilnika žlindre ima tudi majhno obmocje koristnih vrtincnih tokov na vrhu vhoda filtrirne plošce, a hkrati zelo malo prostora za lovljenje in zadrževanje vkljuckov. Pri napolnjenosti 9 % (Slika 18) je filtrirna plošca v celoti zalita, vkljucno z lovilnikom žlindre. V lovilniku se ohrani nekaj majhnih koristnih vrtincnih tokov. Pri napolnjenosti 10 % (Slika 19) je filtrirna plošca popolnoma stabilizirana in vsi vkljucki, ki so vstopili v lovilnik žlindre, bodo ostali ujeti. Dodatek majhne površine za lovljenje žlindre v vhodni odprtini filtrirne plošce izboljša znacilnosti zasnove razdelilnega kanala in zmožnost ujemanja vkljuckov filtrirne plošce. Gre za pomembne koristi ob minimalnem zmanjšanju izkoristka. Primer vodoravne filtrirne plošce Pri vodoravnih zasnovah filtrirnih plošc je mogoce zagotoviti nekaj pomembnih prednosti v povezavi z ucinkovitostjo filtracije preprosto s postavitvijo filtra pod kotom glede na tok. Slika 20 prikazuje standardno vodoravno filtrirno plošco v Adding a small area to trap slag in the filter print inlet improves the flow characteristics of the runner design and the ability of the filter print to trap inclusions. These are significant benefits for a minimal reduction in yield. 6 Horizontal Filter Print Example For horizontal filter print designs, some significant advantages to filtration efficiency can be gained simply by placing the filter at an angle relative to the flow.Figure 20 shows a standard horizontal filter print compared to an angled filter print configuration. Figure 21 shows the flow velocity comparison at 5.5%filled. primerjavi s konfiguracijo filtrirne plošce pod kotom. Slika 21 prikazuje primerjavo hitrosti pretoka pri napolnjenosti 5,5 %. Filter pod kotom lažje sprejme tok in zagotavlja bolj enoten vzorec toka znotraj filtra in nad vhodno površino. Pri napolnjenosti 8,5 % (Slika 22) je profil toka filtrirne plošce pod kotom v celoti vzpostavljen in popolnoma enakomeren. Koristni vrtincni tok je viden na vhodu filtrirne plošce ter povecuje ucinkovitost lovilnika žlindre. Nastanek vrtincnega toka je neposredna posledica filtra pod kotom. Pri 10-odstotni napolnjenosti (Slika 23) obe filtrirni plošci delujeta v enakomernem stanju in ustvarjata enoten vzorec toka. The angled filter more readily accepts the flow and provides a more uniform flow pattern both within and above the filter inlet face. At 8.5% filled (Figure 22), the angled filter print flow profile is fully established, and uniform throughout. A beneficial eddy current is visible within the filter print inlet which enhances the effectiveness of the slag trap. The formation of the eddy current is a direct result of the angled filter. At 10% filled (Figure 23), both filter prints are operating at steady state conditions, and both produce a uniform flow pattern. The angled design does a better job of distributing and minimising the flow energy at the filter inlet face and outlet face. Zasnova pod kotom bolje porazdeli in zmanjša energijo pretoka na vhodni in izhodni strani filtra. Druga prednost filtra pod kotom je, da se tok usmeri cez vhodno stran filtra in potencialno odstrani vse vkljucke, ki so se morda ujeli v sam filter. Ti odstranjeni odmaknjeni vkljucki bi se nato lahko ujeli v vrtincni tok in se mehansko premaknili v lovilnik žlindre. Hitrosti na vhodni strani filtra so prikazane v pticji perspektivi na Sliki 24. (Da bi ustvarili sliko za filter pod kotom, je bila prirezana ravnina zasukana okoli osi y, da se ujema z ravnino filtra.) Slika 24 dejansko prikazuje pticjo perspektivo profila Another advantage of angling the filter is to direct the flow across the filter inlet face to potentially dislodge any inclusions that may have become trapped on the filter itself. These dislodged inclusions could then get entrained into the eddy current and be mechanically moved into the slag trap. The velocities at the filter inlet face are shown in the top view in Figure 24. (To create the image for the angled filter, the clipping plane was rotated around the y-axis to match the plane of the filter.) Figure 24 essentially shows a top view of the flow profile at the filter inlet face. For both cases, the metal flow is clearly moving across the filter inlet face from one end toka na vhodni strani filtra. V obeh primerih se tok kovine ocitno premika prek vhodne strani filtra od enega konca do drugega, kar je bolj izrazito pri filtru pod kotom, kot je razvidno na sliki spodaj. Pri filtru pod kotom se tudi tok skozi filter pomika hitreje, kot je prikazano na Sliki 25. Podobe na Sliki 25 predstavljajo zgolj geometrijo filtra (brez filtrirne plošce ali dovajalnega sistema), podobe pa so zasukane zaradi lažje primerjave. Slika zgoraj prikazuje standardno vodoravno usmerjeno konfiguracijo, medtem ko slika spodaj prikazuje konfiguracijo filtra pod kotom. Filtri so bili prerezani vzdolž središcne crte, lestvica pa je bila prilagojena (zmanjšana) tako, da prikaže smer toka in jasneje razmeji razlike v hitrosti. S tega pogleda slika spodaj prikazuje izpiranje vhodne površine filtra pod kotom, ki jo predstavljajo vzporedni vektorji na vhodni strani filtra in celo nekaj milimetrov znotraj globine samega filtra. Ce primerjamo, nakazujeta samo dva majhna odseka vodoravnega filtra (zgornja slika) vzporedni tok na vhodni strani filtra, pa še to samo na površini samega filtra in ne v njegovi globini. Prednosti mehanskega delovanja premikanja vkljuckov od vhodne površine filtra do lovilnika žlindre so dvakratne: filtru omogoca, da deluje pri najvecjem pretoku, ker je na površini filtra ujetih manj delcev, ki omejujejo pretok kovine skozi filter. Poleg tega lahko v primeru kovin, ki vsebujejo znatne kolicine žlindre, to omogoci delovanje filtra z vecjo zmogljivostjo kot pri standardno orientiranih filtrirnih plošc, saj lahko skozi njih prehaja vec kovine, preden se na koncu zamaši ali obloži z žlindro ali drugimi vkljucki. Na splošno je postavitev filtra pod naklonom glede na tok kovine koristna za hitrost pretoka filtra in ucinkovitost filtracije. to the other, but more prominently in the angled filter case, as seen in the bottom image. For the angled filter, the flow is also moving more quickly through the filter, as shown in Figure 25. The images in Figure 25 represent only the filter geometry (no filter print or gating), and the images are rotated for comparative viewing and as such are not in their normal orientation. The top image represents the standard horizontally oriented configuration while the bottom image represents the angled filter configuration. The filters have been sectioned along the centerline, and the scale has been adjusted (reduced) to show the flow direction and to delineate more clearly the velocity differences. From this view, the bottom image shows the washing of the angled filter inlet face, represented by the parallel vectors on the filter inlet face and even a few millimeters into the filter thickness itself. By comparison, only two small sections of the horizontal filter (top image) show parallel flow at the filter inlet face, and even then, only on the surface of the filter itself, not into the filter thickness. The benefits of the mechanical action of moving inclusions from the filter inlet face to the slag trap are two-fold. This action allows the filter to operate at maximum flow rate because there are fewer particles trapped on the surface of the filter restricting the metal flow through the filter. In addition, for metal-containing significant slag levels, may also allow the filter to operate at a higher capacity than standard filter print orientations because of the opportunity to pass more metal through the filter before ultimately becoming blocked or caked with slag or other inclusions. Overall, placing the filter at an incline relative to the metal stream is beneficial to the filter flow rate capability and filtration efficiency. Sklepi Vcasih se za izboljšanje izkoristka izvedejo spremembe standardnih filtrirnih plošc brez podrobne analize ucinka na lastnosti pretoka tekocine v dovajalnem sistemu. Ta zacetna študija je ovrednotila ucinek vec sprememb zasnove filtrirnih plošc na kakovost pretoka kovine v filtrirni plošci, dovodnem kanalu kot tudi skozi sam filter. Na splošno so zakljucki naslednji: • Velika zmanjšanja vhodnih in izhodnih površin filtrirne plošce ter ostri koti v sami plošci negativno spremenijo znacilnosti toka, kar privede do neenakomernega toka in turbulence. >> Izboljšanje izkoristka je minimalno >> Ni priporocljivo • Lovilnik žlindre pred vhodno površino filtra sproži vrtincni tok, ki se suce levo, ki delujena površino filtra in pomaga pri lovljenju vkljuckov. >> Priporoceno • Pri vodoravnih aplikacijah je nagib filtra glede na tok kovine koristen za zagotavljanje hitrosti pretoka skozi filter in ucinkovito filtracijo. >> Priporoceno Ta prispevek predstavlja zacetno, teoreticno študijo razlicnih modelov filtrirnih plošc SEDEX in njihovega vpliva na znacilnosti pretoka. Nacrtovano je prihodnje delo za pregled dodatnih konceptov oblikovanja in validacijo teh konfiguracij z uporabo staljene kovine. 7 Conclusions Alterations are sometimes made to standard filter prints to improve yield without careful analysis of the effect on the fluid flow properties of the gating system. This initial study evaluated the effect of several filter print design changes on the quality of metal flow in the filter print, the runner system, and through the filter itself. In general, the conclusions are as follows: • Large reductions in filter print inlet and outlet areas, and sharp angles within the print itself adversely alter the flow characteristics resulting in non-uniform flow and turbulence >> Yield improvement is minimal >> Not recommended • A slag trap designed before the filter inlet face induces a counter-clockwise eddy current that washes the filter face and assists with the trapping of inclusions. >> Recommended • In horizontal applications, angling the filter relative to the metal stream is beneficial to the filter flow rate capability and filtration efficiency. >> Recommended This paper constitutes the initial, theoretical study of various SEDEX filter print designs and their effect on flow characteristics. Future work is planned to review additional design concepts and validate these configurations with molten metal. Viri / References 1. Giebing, S., Baier,, A. “SEDEX – Process Reliability Through Effective Quality Control,” Foundry Practice, vol. 254, pp. 4 (June 2011). 2. Morales, R.D., Adams, A., Dickinson, B. “Enhancing Filtration Knowledge to Improve Foundry Performance”, Foundry Practice, Special Edition, pp. 21 (May 2008). 3. Baier, A. “The Influence of Filter Type and Gating System Design on the Machinability of Vertically Parted Grey Iron Castings”, Foundry Practice, Special Edition, pp. 29 (May 2008). 4. Taylor, K.C., Baier, A. “Application of SEDEX Ceramic Foam Filters on Vertically Parted Moulds Such as Disamatics”, Foundry Practice, vol. 238, pp. 10 (March 2003). 5. Midea, A.C. “Pressure Drop Characteristics of Iron Filters”, AFS Transactions, 01-042, (2001). 6. Brown, J.R. “Foseco Ferrous Foundryman’s Handbook”, pp. 250-266, Butterworth-Heinemann, Woburn, MA, 2000. 7. Park, W.H. “SEDEX Ceramic Foam Filter Applications in Korea”, Foundry Practice, vol. 221, pp. 2 (March 1991). 8. Matsuo, H. “SEDEX Ceramic Foam Filter Applications on Regular Production Casting in Japan, Foundry Practice, vol. 220, pp. 4 (September 1990). 9. Kallisch, W. “SEDEX – AFilter with Authority”, Foundry Practice, vol. 217, pp. 18 (April 1989). 10. Rietzscher, R. Sipl. – Ing. “The Filtration of Molten Iron”, Foundry Practice, vol. 212, pp. 5 (March 1986). 11. Heine, R.W., Loper, C.R., Rosenthal, P.C. “Principles of Metal Castings”, pp. 223, McGraw-Hill Book Company, New York, 1967. S. K. Subbarayalu, M. Manapuram North Eastern Regional Institute of Science and Technology, India / Indija Oblikovanje in izdelava ulitka bata motorja indijskega lahkega motornega vozila s postopkom tridimenzionalnega tiska: študija Design and Manufacture of Engine Piston Casting of Indian Light Motor Vehicle by Three-Dimensional Printing Process: A Study Povzetek Indija je cetrti najvecji proizvajalec lahkih motornih vozil (LMV) na svetu. V Indiji se letno proizvede okoli štiri milijone lahkih motornih vozil. Avtomobil je vozilo s kolesi, ki nosi lastno težo in je namenjeno prevažanju med destinacijami. Sestavljen je iz pribl. 15.000 delov, ki tvorijo njegove podsisteme, kot so motor, pogonski sistem, vzmetenje, zavorni sistem, elektricni sistemi, šasija in karoserija. Beseda »avtomobil« izhaja iz grške besede »autos«, ki pomeni »jaz«, in latinske besede »mobiles«, ki pomeni »gibljiv«. Avtomobile lahko glede na zmogljivost razvrstimo na dvokolesnike, trikolesnike, lahka motorna vozila, gospodarska vozila (tovornjaki in avtobusi). Lahka motorna vozila poganjajo motorji z notranjim zgorevanjem (ICE), ki delujejo na bencin, dizel, plin ali elektriko. Podsisteme motorjev z notranjim izgorevanjem sestavljajo okrov motorja, glava valja, bat z ojnico, rocicna gred vkljucno z odmicno gredjo in ventili. Bat je del motorja, ki toplotno in tlacno energijo, ki nastane pri zgorevanju goriva, pretvori v mehanska dela. Bat motorja je najkompleksnejši sestavni del pri avtomobilu. Izmed vseh sestavnih delov zahtevajo bati najvec spretnosti za nacrtovanje ulitka, ki obsega tradicionalne proizvodne postopke, in sicer litje v pesek, tlacno litje in litje s stiskanjem. Tradicionalne metode so dolgotrajnejše, med postopki pa se zavrže vecja kolicina kovine. Zato se je treba poslužiti najnovejšega proizvodnega postopka, ki se imenuje tridimenzionalno tiskanje (3DPP). Gre za novonastajajoco proizvodno tehnologijo, ki se uporablja za izdelavo dejanskih delov z uporabo podatkov CAD, in sicer z dodajanjem materiala razlicnih oblik (trdni, tekoci in praškasti) v plasteh. S tehnologijo 3-D tiskanja je mogoce natisniti predmet plast za plastjo z nanosom materiala neposredno iz racunalniško podprtega modela. Vecina proizvajalcev batov se poslužuje obicajnih proizvodnih metod. Zato smo v tem prispevku proucili nacrtovanje in izdelavo ulitja bata s pomocjo tehnologije 3DPP. Kljucne besede: avtomobil, lahko motorno vozilo, motor z notranjim izgorevanjem, zasnova bata, postopek 3-D tiskanja Abstract India is the fourth largest light motor vehicle (LMV) manufacturer in the world. It produces around four million LMVs annually. An automobile is a wheeled vehicle that carries its own weight and transports from one destination to another. It consists of around 15,000 parts for its sub-systems like engine, transmission, suspension, brake system, electrical systems and chassis and body. The word ‘automobile’ is derived from Greek ‘autos’ meaning ‘self’, and Latin ‘mobiles’ meaning ‘moveable’. Automobiles may be classified from the point of capacity are two-wheelers, three-wheelers, light motor vehicles, and commercial vehicles (trucks and buses). LMVs are propelled by internal combustion engines (ICE) which are fueled by either petrol, diesel, gas, and electricity. ICE sub-systems comprise of cylinder block, cylinder head, piston with connecting rod, and crankshaft including camshaft and valves. The piston is the part of the engine which converts heat and pressure energy liberated by fuel combustion into mechanical works. An engine piston is the most complex component among the automobiles. Out of these components pistons are required high skill to design the casting which involves traditional manufacturing processes namely sand casting, pressure die casting, and squeezed casting. The traditional methods are time-consuming and more wastageof metal. So, there is a need to go for the latest manufacturing process called three-dimensional printing process (3DPP). It is an emerging manufacturing technology used to fabricate real-life parts, using CAD data by adding material in layer fashion in distinct forms (solid, liquid, and powder). 3-D printing technology can print an object layer by layer deposition of material directly from a computer-aided design model. Most of the piston manufacturers have been following conventional methods for the manufacture of piston casting. Hence in the present work, an attempt has been made to study the design and manufacturing of piston casting by 3DPP. Keywords: Automobile, Light Motor Vehicle, I C Engine, Piston design, 3 D Printing Process Uvod Indijska avtomobilska industrija je v letu 2020 proizvedla približno [1–3] 26,36 milijona vseh avtomobilov, vkljucno s 3,42 milijona (13 %) lahkih motornih vozil. Avtomobil [4] je vozilo na kolesih, ki nosi lasten motor in prevaža potnike od enega cilja do drugega. Avtomobil je sestavljen iz sedmih glavnih podsistemov: motorja, pogonskega sistema, šasije, karoserije, zavornega sistema, vzmetenja in elektricnega sistema. Avtomobile lahko glede na zmogljivost razvrstimo na dvokolesnike in trikolesnike, lahka motorna vozila in gospodarska vozila. Indijski tržni delež avtomobilov je prikazan na Sliki 1. Levji delež trga predstavljajo dvokolesniki (81 %), ki jim sledijo lahka motorna vozila (13 %). Sistem lahkega motornega vozila [5] je sestavljen iz šasije, motorja, elektricnega sistema, pogonskega sistema, sistema vzmetenja, zavornega sistema in karoserije. Šasija obsega motor, pogonski sistem, sistem vzmetenja, krmilni sistem in zavore. 1 Introduction Indian automobile industry produces around [1-3] 26.36 million of all automobiles including 3.42 million (13%) LMVs in the year 2020 AD. An automobile [4] is a wheeled vehicle that carries its own motor and transports passengers from one destination to another destination. An automobile consists of major seven sub­ systems like engine, transmission system, chassis, body, braking system, suspension system and electrical system. Automobiles may be classified from the point of capacity as two and three wheelers, light motor vehicles, and commercial vehicles. The Indian market share of automobiles are depicted in the Figure 1. Lion’s share of market is two wheelers (81%) followed by LMVs (13%). An LMV system [5] consists of a chassis, engine, electrical system, transmission system, suspension system, brake system, and body. The chassis houses the engine, transmission system, suspension system, Motor zagotavlja pogonsko moc za vse razlicne funkcije, ki jih mora vozilo opravljati. Na splošno je motor sestavljen iz motorja z notranjim zgorevanjem, ki lahko obsega vžig s svecko ali kompresijski vžig. Elektricni sistem zagotavlja elektriko za zagon motorja, polnjenje akumulatorja in napaja razsvetljavo in drugo dodatno opremo. Prenosni sistem je sestavljen iz sklopke, menjalnika, ki zagotavlja razlicna razmerja izhodnega navora, kardanske gredi za prenos navora od menjalnika do zadnje osi in diferenciala do pogonskih koles. Blažilni sistem, ki absorbira udarce pnevmatik in koles na neravnem cestišcu. Zavorni sistem je namenjen zaustavitvi vozila na najmanjši možni razdalji. Karoserija obsega prostore za motor, potnike ter prtljago ali tovor. Proizvodnja lahkih motornih vozil je med letoma 2005 in 2021 nenehno narašcala, v casu pandemije covida pa je upadla. Lahka motorna vozila se izdelujejo z litjem, oblikovanjem, spajanjem in rezanjem kovin ter s kombinacijo teh postopkov. Lahka motorna vozila glede na maso v vec kot 60 % sestavljajo kovinski ulitki. Nastajajoce tehnologije, kot sta aditivna proizvodnja ali 3-D tiskanje [6], se danes uporabljajo zaradi manjše potrebe po steering system and brakes. The engine provides the motive power for all the various functions that the vehicle may be called upon to perform. Generally, an engine consists of an internal combustion engine which may either spark ignition or compression ignition engine. The electrical system gives electricity for cranking the engine, charging the battery and giving power to lighting and other accessories. The transmission system consists of a clutch, a gearbox that provides different ratios of torque output, a propeller shaft to transmit the torque from gearbox to the rear axle, and a differential gear to the driving wheels. The suspension system, absorbs the shock of the tires and wheels meeting the uneven surface of the road. The brake system is provided to stop the vehicle within the smallest possible distance. The body provides compartments for the engine, passengers, and luggage or cargo. The LMV production has been increasing from 2005 to 2021 AD continuously but declined during the covid pandemic time. LMVs are manufactured by casting, forming, joining, and metal cutting and their combinations. More than 60% are metal castings by mass of LMV. Emerging orodju, proizvodnih korakih in odpadkov. 3-D tiskanje, poznano tudi pod imenom aditivna proizvodnja (AM), je »postopek nanašanja materialov plast za plastjo za izdelavo koncnih komponent na podlagi modela 3-D CAD«. S programsko opremo se oblikuje objekt CAD, ki se nato poveže s 3-D tiskalnikom. Oblikovalcem omogoca prilagodljivost za pripravo prilagojene oblike izdelka in posledicno tiskanje sestavnih delov, ki jih morda ni mogoce izdelati z drugimi obicajnimi proizvodnimi metodami. Uporaba tradicionalnih proizvodnih metod predvideva sestavljanje razlicnih delov, medtem ko je mogoce s 3-D tiskanjem velike kose koncne komponente natisniti z enim samim postopkom. Kompleksne in zapletene komponente je mogoce izdelati z znatnim zmanjšanjem casa izdelave, stroškov in zavrženega materiala. Scasoma se je 3-D tiskanje razvilo v uporaben postopek za izdelavo izdelkov za koncne uporabnike v razlicnih panogah. Izdelava delov s to tehniko omogoca v primerjavi s tradicionalnimi proizvodnimi postopki veliko prednosti. Malo verjetno je, da bo 3-D tiskanje nadomestilo številne tradicionalne proizvodne metode, vendar obstaja veliko podrocij za uporabo, kjer je mogoce s 3-D tiskalnikom iz funkcionalnega materiala hitro in z visoko natancnostjo proizvesti del. Oblikovalcem omogoca razumevanje prednosti 3-D tiskanja ugodnejše odlocanje pri izbiri proizvodne tehnike, kar vodi v proizvodnjo optimalnega izdelka. Ena od glavnih prednosti aditivne proizvodnje je hitrost, s katero je mogoce izdelati dele v primerjavi s tradicionalnimi proizvodnimi metodami. Zapletene oblike je mogoce naložiti iz modela CAD in jih natisniti v nekaj urah. Prednost tega je hitro preverjanje in razvoj razlicnih dizajnov. Medtem ko je v preteklosti morda trajalo nekaj dni ali celo tednov, preden smo prejeli prototip, technologies like Additive Manufacturing or 3-D printing [6] are used nowadays because of less tooling, manufacturing steps, and less wastage. 3-D printing, also known as additive manufacturing (AM), is “a process of depositing the materials layer by layer to make final components from 3 D CAD model”. The CAD software design the object, which is then interfaced with a 3-D printer. It gives flexibility to designers to create customized product designs and in turn print the components which may not be possible to be manufactured by any conventional manufacturing methods. Unlike traditional manufacturing methods, the different parts are assembled, whereas 3-D printing can print large pieces of a final component in a single process. Complex and intricate components can be manufactured with a substantial reduction in manufacturing time, costs, and material wastage. It has evolved over a period of time into a matured process for being able to fabricate end-use products in various industries. There are plenty of advantages compared to traditional manufacturing processes while manufacturing the parts with this technique. 3-D printing is unlikely to replace many traditional manufacturing methods yet there are many applications where a 3-D printer is able to deliver a design quickly, with high accuracy from a functional material. Understanding the advantages of 3-D printing allows designers to make better decisions when selecting a manufacturing technique that results from delivery of the optimal product. One of the main advantages of additive manufacturing is the speed at which parts can be produced compared to traditional manufacturing methods. Complicated designs can be uploaded from a CAD model and printed in a few hours. The advantage of this is the rapid verification and development je lahko z aditivno proizvodnjo model v rokah oblikovalca že v nekaj urah. Medtem ko stroji za bolj industrijsko naravnano aditivno proizvodnjo potrebujejo dlje casa za tiskanje in naknadno obdelavo dela, ponuja zmožnost izdelave funkcionalnih koncnih delov majhnih do srednjih kolicin veliko prednost z vidika prihranka casa v primerjavi s tradicionalnimi proizvodnimi tehnikami. Odpira nove priložnosti in daje upanje številnim možnostim za podjetja, ki želijo izboljšati ucinkovitost proizvodnje. Omogoca tiskanje kovin, uveljavljene termoplastike in keramike. Z uporabo te metode lahko industrije izboljšajo ucinkovitost svojih proizvodnih linij. Z uvedbo tehnologije 3-D tiskanja se bo povecala hitrost proizvodnje, hkrati pa se bodo zmanjšali stroški. Zaradi predlogov potrošnikov so specifikacije proizvedenih koncnih izdelkov skladne s potrebami narocnikov. Uporabna je v avtomobilski industriji, kmetijstvu, zdravstvu in vesoljski industriji, in sicer za masovno prilagajanje in proizvodnjo vseh vrst odprtokodnih modelov. Socasno pa je ta metoda ob prilagoditvi primerna tudi za proizvodno industrijo. Ta tehnika na primer vpliva na gospodarstva držav, ki so odvisne od velikega števila nizkokvalificiranih delovnih mest. Na splošno je tehnologija 3-D tiskanja dandanes postala prepoznana kot zmogljiva in izvedljiva možnost v razviti proizvodni industriji. Pregled literature R Dolan in sod. [7] so v študiji zasnove bata za težke obremenitve IAV prikazali, da 3-D tiskanje omogoca popolnoma nov pristop k zasnovi bata. S to novo tehnologijo je mogoce izdelati optimizirane zasnove zgorevalnih komor, ki niso rotacijsko simetricne in imajo lahko zajede, kar vodi do of design ideas. Where in the past it may have taken days or even weeks to receive a prototype, additive manufacturing places a model in the hands of the designer within a few hours. While the more industrial additive manufacturing machines take longer to print and post process a part, the ability to produce functional end parts at low to mid volumes offers a huge time saving advantage when compared to traditional manufacturing techniques. It opens new opportunities and gives hope to many possibilities for companies looking to improve manufacturing efficiency. It can print metals, traditional thermoplastics, and ceramics. By using this method, the industries may improve the efficiency of the production line. The adoption of 3-D printing technology will increase production speed while reducing costs. With the inputs from the consumers, the specifications of end product manufacturers as per the needs of the customer. It finds application in the automotive industry, agriculture, healthcare, and aerospace industries for the mass customization, and production of any type of open-source design. Simultaneously, the adaption of this method is also invited in the manufacturing industry. For instance, this technique sometimes affects the economy of countries that rely on a large number of low skilled jobs. In general, 3-D printing technology has become prominent now-a-days as a powerful and feasible technique in advanced manufacturing industry. 2 Literature Review R Dolan et al., [7] demonstrated by the IAV heavy-duty piston design study, 3-D printing enables a completely new approach to piston design. Optimized designs of piston bowl shapes, which are no longer rotationally symmetrical and can have undercuts, are znatnega izboljšanja mešanja zraka in gori­ va ter procesa zgorevanja. Rakesh Kumar in sod. [8] so izpostavili razlicne aplikacije 3-D tiskalnikov v razlicnih sektorjih. Povzeli so tudi prednosti, slabosti, prihodnost in izzive, da bi ta njihov dokument lahko postal vodilo za prihodnje raziskovalce, ki delajo na podrocju 3-D tiskanja. Venkat Ramana in sod. [9] so zasnovali rocicno gred za vecvaljni motor in njen 3-D model ustvarili s programsko opremo za modeliranje CATIA V5R20. Vinod Gokhare in sod. [10] so predstavili zgodovino 3-D tiskanja in proucili proces 3-D tiskanja ter kateri materiali se uporabljajo pri izdelavi 3-D tiskanih predmetov in med njimi izbrali najboljše materiale, ki so primerni za naš 3-D tiskalnik. A. Dalvi [11] je zakljucil, da je akrilonitril butadien stiren najmocnejši material za 3-D tiskanje, ki lahko prenese obremenitev 47 KN do napetosti tecenja. Rezultati FEA kažejo, da je akrilonitril butadien stiren mocan, ko je izpostavljen natezni ali tlacni obremenitvi zaradi 3-D tiskanja. SK Subbrayalu in sod. [12] so razpravljali o raziskovalnih vprašanjih in izzivih avtomobilskih livarn, analizirali komponente motorja in njihove materiale ter vpliv na porabo goriva. Uporaba neželeznih kovin in zlitin ter strojev za tlacno litje vodi v manjšo porabo energije in krajši cas cikla. Brodarac in sod. [13] so raziskali zaporedje strjevanja zlitine AlSi11 in dolocili mikrostrukturne sestavine s termodinamicnim modeliranjem in diferencialno kalorimetrijo. Razpravljali so tudi o odstotku aluminijevih zlitin za evropske avtomobile. possible with this new technology and lead to significant improvement in air-fuel mixing and combustion process. Rakesh Kumar et al. [8] highlighted the distinct 3-D printer applications in different sectors. Also summarizes the merits, demerits, future, and challenges, so that this review paper could become the torch bearer for the futuristic researchers working in the area of 3-D printing. Venkat Ramana et al., [9] designed a crankshaft for multi-cylinder engine and its 3-D-models were created using modeling software CATIA V5R20. Vinod Gokhare et al. [10] presented the history of 3-D printing and studied about the process of 3-D printing and what materials are used in the manufacture of 3-D printed objects, and select the best materials among them which are suitable for our 3-D printing machine. A Dalvi [11] concluded that Acrylonitrile Butadiene Styrene is the strongest 3-D printing material that can carry a load of 47 KN up to Yield stress. FEA results show that Acrylonitrile Butadiene Styrene is strong when subjected to tensile or compressive loading 3-D Printing. S K Subbrayalu et al.,[12] discussed research issues and challenges of Automotive Foundries, analysed engine components and their materials, and effect on fuel consumption. The use of nonferrous metals and alloys and die casting machines reduces energy consumption and cycle time. Brodarac et al., [13] investigated the solidification sequence of AlSi11 alloy and established microstructural constituents with thermodynamic modeling and differential calorimetry. Al alloys percentage for European cars was also discussed. Tridimenzionalni proces tiskanja in njegovi podsistemi 3.1 Zgodovina procesa tridimenzionalnega tiskanja Leta 1986 je Charles W. Hull izumil in patentiral prvi znani 3-D tiskalnik. V svojem patentu je opisal postopek stereo litografije, s katerim je mogoce konstruirati dele s strjevanjem plasti fotopolimera (smole). Po treh letih je leta 1989 Scott Crump patentiral še en 3-D tiskarski stroj, ki deluje na podlagi metode ciljnega nanašanja (FDM). Nato je Adrian Bowyer razvil napravo Rep Rap (Replicating Rapid Prototyper), za katero je na voljo brezplacna programska oprema z odprtokodno kodo, vecina delov pa je izdelana s postopkom aditivne proizvodnje. Na podlagi teh neprekinjenih izboljšav so se znižali stroški. Najvecji industrijski 3-D tiskarski sistem na svetu je sistem VX 4000 podjetja Voxeljet AG iz Nemcije s prostornino 4000x2000x1000 mm, ki je namenjen tiskanju pešcenih jeder za livarsko industrijo, izdelan pa je bil leta 2020. Razlicne industrijske aplikacije [14], kot so avtomobilska, vesoljska, elektronska, medicinska, akademska, vojaška, arhitekturna in druge industrije, so predstavljene na Sliki 2. To pomeni, da je postopek tiskanja 3-D zaradi kolicin zavrženega materiala in masovne proizvodnjo z manj delovne sile široko sprejet v razlicnih industrijah. Avtomobilska in vesoljska industrija sta vodilni panogi, kjer se ta proces uporablja za zvecanje proizvodnje komponent. 3.2 Klasifikacija postopkov tridimenzionalnega tiskanja 3-D tiskanje lahko na splošno razvrstimo v dva razreda, in sicer glede na agregatno 3 Three-Dimensional Printing Process and its Sub-Systems 3.1 History of Three-Dimensional Printing Process In 1986, Charles W. Hull invented and patented the first known 3-D printer. In his patent, he narrated the stereo lithography process where it is possible to construct parts by solidifying layers of a photopolymer (resin). After three years, another 3-D printing machine was patented by Scott Crump that uses Fused Deposition Modelling (FDM) in 1989. Later Adrian Bowyer developed Rep Rap (Replicating Rapid Prototyper), where free equipment software is provided with open-source code and the majority of parts are produced through Additive Manufacturing Process. With these continuous improvements first low cost. The world’s largest industrial 3-D printing system Voxeljet AG,2021, VX 4000 system for a volume of 4000x2000x1000 mm for core printing in in Germany in 2020. Various industry applications [14] such as automotives, aerospace, electronics, medical, academic, military, architecture and other industries are presented in Figure 2 and this implies 3DP process is widely accepted by the different industries owing wastage of material as well as mass production with less man power. Automobile industries and aerospace industries are the leading industries where this process finds the application towards the augmenting the production of components. 3. Classification of Three-Dimensional Printing Processes 3-D printing can be broadly classified into two classes, namely, on the physical state of the raw material, i.e., liquid-, solid- or Slika 2. Industrijske aplikacije 3-D tiskanja Figure 2. Industrial applications of 3-D printing Slika 3. Razvrstitev postopka 3-D tiskanja Figure 3. Classification of 3-D Printing Process stanje surovine, torej postopke, ki predvidevajo uporabo tekocin, trdnih snovi ali praškastih materialov, in glede na nacin, kako se snov spoji na molekularni ravni, tj. toplotno, z ultravijolicno svetlobo, laserjem ali elektronskim snopom. Najpogosteje uporabljeni postopki 3-D tiskanja so razdeljeni v naslednje tri kategorije, in sicer na trdni osnovi (FDM), na tekoci osnovi (SLA, IJP) in na osnovi praškastih materialov (SLM, SLS, EBM), kot je prikazano na Sliki 3. 3.3 Materiali, uporabljeni za tridimenzionalno tiskanje Tehnologija 3-D tiskanja kovin je pridobila pozornost v vesoljski, avtomobilski, medicinski in proizvodni industriji, in sicer zaradi prednosti, ki jih proces zagotavlja. Materiali, ki se uporabljajo v tiskanju 3-D, so aluminijeve zlitine, zlitine na osnovi kobalta, zlitine na osnovi niklja, nerjavna jekla in titanove zlitine. Uporablja se pri visokih napetostih in visokih delovnih temperaturah ter pogojih visokih napetosti za letalske in vesoljske komponente. Tehnologije 3-D tiskanja se pogosto uporabljajo za proizvodnjo polimernih komponent za oblikovanje prototipov funkcionalnih struktur s kompleksnimi geometrijami. Z uporabo metode ciljnega nanašanja (FDM) je mogoce 3-D tiskanje izkoristiti za nanašanja zaporednih plasti ekstrudiranega termoplasticnega filamenta, npr. iz polilakticne kisline (PLA), akrilonitril butadien stirena (ABS), polipropilena (PP) ali polietilena (PE). 3.4 Ulitek bata motorja lahkega motornega vozila Bat, ki deluje [15–16] pri visoki temperaturi, visokem tlaku, v korozivnem okolju in powder-based processes, and on the way in which the matter is fused on a molecular level, i.e., thermal, ultraviolet light, laser, or electrons beam. The most commonly applied 3-D printing processes are divided into the following three categories such as solid based (FDM), liquid-based (SLA, IJP), and powder base (SLM, SLS, EBM) are shown in Figure 3 3.3 Materials used for Three-Dimensional Printing Metal 3-D printing technology gain industrial attention in aerospace, automobile, medical application, and manufacturing industry because the advantages existing by this process. The materials 3-D printed are aluminium alloys, cobalt-based alloys, nickel-based alloys, stainless steels, and titanium alloys. It is used in high stresses and high operating temperatures and high stress conditions for aerospace components. 3-D printing technologies are widely used for the production of polymer components to form prototypes to functional structures with difficult geometries. By using fused deposition modeling (FDM), it can form a 3-D printer through the deposition of successive layers of extruded thermoplastic filament, such as polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), polypropylene (PP) or polyethylene (PE). 3.4 Light Motor Vehicle Engine Piston Casting Piston, which operates [15-16] at high temperature, high pressure, corrosive, and wears conditions whilst operating at high speed, is the most significant portion of the motor. The pistons are located at the center of the internal combustion engine and pod pogoji obrabe, kadar deluje z visoko hitrostjo, je najpomembnejši del motorja. Bati se nahajajo v središcu motorja z notranjim zgorevanjem, povratno gibanje cela bata, stranske stene in zgornjih obrockov pa ustvarja znaten pritisk. Za zmanjšanje visokih stopenj izpustov ogljika mora biti zgornji del bata zelo tanek. Da bi izpolnili povpraševanje po standardih Euro, morajo batni materiali in proizvodni postopki izpolnjevati stroge standarde, da bi ostali na pravi poti. Biti morajo izjemno mocni, robustni in majhni. Zasnova bata obsega izracune bata, premera, skupne dolžine, dolžine valja, debeline krone, plašca, globine utora obrocka, premera bata, vrzeli med dolžino obrockov in debeline zgornje površine med utorom. 3.5 Postopek tridimenzionalnega tiskanja 3-D tiskanje je aditivni proizvodni proces, s katerim se dodajajo številne plasti materialov za plastmi, dokler izdelek ni dokoncan. 3-D tiskanje se izvaja z uporabo racunalniško podprtega oblikovanja (CAD) ali laserskega skeniranja za ustvarjanje predmeta 3-D. Oblikovalski model je razrezan na vec ravnin ali plasti, ki 3-D tiskalnik usmerjajo pri zaporednem nanašanju tankih plasti materiala eno na drugo, dokler ni izdelan koncni izdelek. Gre za proces 3-D izdelave predmeta od spodaj navzgor z nanašanjem plasti. Metoda je zato okolju prijaznejša, saj se v primerjavi s tradicionalno proizvodnjo ustvari zelo malo odpadnega materiala. Obicajni proizvodni postopki, kot sta litje in formanje, ustvarijo predmet iz surovin v razsutem stanju, medtem ko se s subtraktivno strojno obdelavo, kot sta rezkanje in struženje, ustvari predmete od zgoraj navzdol z odstranjevanjem materialov, dokler ne nastane koncni izdelek. the reciprocating movement of the piston crown, sidewall, and top rings will create significant pressure. The piston top ground has to be very thin to decrease high carbon (HC) emissions. To meet the demand Euro standards, piston materials and production procedures must meet rigorous standards in order to stay on track. They must be extremely strong, robust, and light in weight. Piston design involves calculations of the piston, diameter, total length, barrel length, head thickness, skirt, depth of ring groove, piston pin diameter, the gap between rings length, and top land thickness. 3.5 Three-Dimensional Printing Process 3-D printing is an additive manufacturing process that adds many layers of materials upon layers until the product is built. 3-D printing uses a computer-aided design (CAD) or laser scan to create a 3-D object. The design model is sliced into several planes or layers, which direct the 3-D printer in depositing the successive thin layers of material upon each other to construct a final product. The 3-D process creates the object from the bottom-up by adding layers. So, it is more efficient of the environment because there is very little waste material compared to traditional manufacturing. Conventional manufacturing processes such as casting and forming create the object from bulk raw materials, while subtractive machining such as milling, and turning create the objects from the top-down by subtracting and removing materials until getting the final product. 3-D printing process steps for LMV piston are shown in Figure 4. Various steps involve right from piston design to 3-D printing of the final product. In the first step the piston is designed as per the LMV specification followed by 3 CAD Slika 4. Diagram poteka postopka 3-D tiskanja Figure 4. Flow diagram of 3-D printing process Koraki postopka 3-D tiskanja za bat lahkega motornega vozila so prikazani na Sliki 4. Ti razlicni koraki obsegajo vse od oblikovanja bata do 3-D tiskanja koncnega izdelka. V prvem koraku je bil zasnovan bat po specifikaciji lahkega motornega vozila, sledil je model 3-D CAD, pripravljen z uporabo programa za 3-D modeliranje. Program ustvari datoteko STL, ki se nato pošlje 3-D tiskalniku. Ob tem programska oprema razreže dizajn na stotine ali bolj verjetno na tisoce horizontalnih plasti. Te plasti se natisnejo ena na drugo, dokler ni izdelan tridimenzionalni predmet. Oblikovalski model je razrezan na vec ravnin, ki 3-D-tiskalnik usmerjajo pri zaporednem nanašanju tankih plasti materiala eno na drugo, dokler ne proizvede koncni ulitek bata. Oblikovanje in izdelava ulitka bata lahkega motornega vozila s 3-D tiskanjem 4.1 Zasnova bata V preglednicah 1 in 2 je predstavljena kvantificirana in napovedana proizvodnja lahkih motornih vozil in potrebno letno models using a 3-D modeling program. The program creates an STL file which is sent to the 3-D printer. Along the way, software slices the design into hundreds, or more likely thousands, of horizontal layers. These layers will be printed one on top the other until the 3-D object is made. The design model is sliced into several planes, which direct the 3-D printer in depositing the successive thin layers of material upon each other to construct a final piston casting. 4 Design and Manufacturing of Piston Casting of Light Motor Vehicle by 3-D Printing 4.1 Piston Design Production of LMVs and number of pistons required annually quantified and forecasted and is presented in Tables 1 and 2. LMV engine specification for the 3-cylinder engine is presented in Table 3. Piston design and process parameters and calculations are shown in Table 4. The piston drawing is shown in Figure 5. Slika 5. Specifikacije konstrukcije bata lahkega motornega vozila v mm Figure 5. LMV piston design specifications in mm število barov. Specifikacija motorja lahkega motornega vozila za 3-valjni motor je predstavljena v Preglednici 3. Zasnova bata in procesni parametri ter izracuni so prikazani v Preglednici 4. Skica bata je prikazana na Sliki 5. 4.2 Izdelava ulitkov batov s tehnologijo 3DPP Bate izdelujemo s tehnikami litja v pesek, kokilami, stiskanjem ali z metalurgijo prahu. Te razlicne proizvodne tehnologije, ki se uporabljajo za izdelavo avtomobilskih batov, imajo razlicne vplive na mikrostrukturo ter fizikalne in mehanske lastnosti. Stiskanje in kokilno litje veljata za konvencionalni proizvodni tehnologiji. Po drugi strani pa so se pojavili novi proizvodni procesi, npr. tlacno litje (PDC), ki je avtomatiziran industrijski proces. Pri obicajnem postopku tlacnega litja se staljena kovina vlije v brizgalni tulec iz lonca, potem ko kokila zaprta. Kovina se v kokilo potisne z gibanjem bata, ki premicni del prisili, da se poravna s fiksnim delom. Kovinski praškasti material se uporablja kot surovina v aditivni proizvodnji (AM). Izkazovati mora dobre lastnosti tecenja, sintranja in polnjenja. Da bi prilagodili razlicne materiale, so bile razvite razlicne tehnologije aditivne proizvodnje. Metoda ciljnega nanosa se obsežno uporablja za izdelavo prototipov iz materiala PLA. S 3-D tiskanjem je mogoce plast za plastjo natisniti celotendel v enem kosu. Zagotavlja prednost z vidika prilagodljivosti oblikovanja v proizvodnji majhnih serij delov. V tem prispevku se pri metodi tridimenzionalnega 4.2 Manufacture of Piston Casting by 3DPP Pistons are manufactured by sand casting, gravity dies, pressure die, squeeze casting, or powder metallurgy techniques. These varieties of manufacturing techniques are employed for the fabrication of automobile pistons, each technique has its own impact on the microstructure, and physical and mechanical properties. Squeeze casting and gravity die casting are both considered conventional production technologies. New production processes, on the other hand, have emerged pressure die casting (PDC) is an automated industrial process. In a conventional die casting process, molten metal is poured into the shot sleeve by a ladle after the die is closed. The metal is driven into the die by a plunger (piston) movement, forcing the mobile part to align with the fixed part. Metal powders are used as a raw material in additive manufacturing (AM). It must consist of good flow, sintering, and packing properties. In order to accommodate different materials different AM techniques evolved. The fused deposition method is a widely used prototyping technology that uses PLAas a material. 3-D printing is capable to print the whole part in one structure layer Preglednica 1. Proizvodnja lahkih motornih vozil in ocena potreb po batih v letih 2005–2021 Table 1. Production of LMVs and estimation of piston requirement during 2005-21 Kategorija avtomobilov / Category of Automobile Proizvodnja lahkih motornih vozil v milijonih / LMV production in millions Proizvodnja lahkih motornih vozil od 2005 do 2020 / Light motor vehicle production from 2005 to 2020 46,30 Skupna proizvodnja batov za motor lahkega motornega vozila, (46,3x3) / Total piston production for LMV engine, (46.3x3) 138,9 Potrebni bati (10 %) za rezervne dele za obstojeca lahka motorna vozila / Piston required (10%) for spares for existing LMVs 13,89 Proizvodnja lahkih motornih vozil v letu 2021 / LMV production in 2021 3,06 Proizvodnja batov za trivaljne motorje za leto 2021 / Piston production for three cylinder engine for 2021 9,18 Skupna zahteva po batih na leto / Total piston requirement per annum 161,97 Enacba napovedane proizvodnje lahkih motornih vozil / Forecasted LMV production equation 0,1587x+1,5408 Enacba napovedane proizvodnje batov / Forecasted piston production equation 0,4869x+4,9523 Preglednica 2. Napovedovanje proizvodnje lahkih motornih vozil in potreb po batih za obdobje od 2022 do 2025 Table 2. Forecasting of LMV Production and Piston Requirement for 2022 to 2025 Letna proizvodnja / Annual production Enacbe napovedovanja proizvodnje / Forecasting production equations Ocenjena prihodnja proizvodnja v milijonih / Estimated future production in millions FY22 FY23 FY24 FY25 Letna proizvodnja lahkih motornih vozil / Annual production of LMVs 0,1587x+1,5408 4,24 4,39 4,55 4,71 Letna proizvodnja batov / Annual production of pistons 0,4869x+4,9523 13,23 13,71 14,20 14,69 (3-D) tiskanja, razviti za izdelavo ulitka bata, dolžina hoda bata pri nizki hitrosti do tocke prehoda imenuje dolžina prve faze, tlak brizganja se zmanjša na koncu, ko je v formo vbrizgana skoraj vsa tekoca kovina, ki se nato strdi. Zaradi obsežne uporabe digitalne tehnologije v številnih aplikacijah se je priljubljenost aditivne proizvodnje (AM) ali tridimenzionalnega tiskanja (3DP) by layer. It gives an advantage in design flexibility for low- volume customized parts. In the present work three-dimensional (3­ D) printing method developed for piston casting the length of travel of the piston in the low velocity up to the changeover point is known as the first phase length and the injection pressure decreases at the end when nearly all the liquid metal is injected into the die and solidifies. po vsem svetu povecala. Gre za proces konstruiranja dejanskih elementov na podlagi digitalnih informacij kos za kosom, vrstico za vrstico, površino za površino ali plast za plastjo, in sicer z uporabo orodij in programov za digitalno 3-D modeliranje. 3-D tiskanje je vrsta tiskanja, s katerim je mogoce izgraditi ali poustvariti samostojece kompleksne strukture iz enega samega kosa. Velikost 3-D tiskalnika in materiali, ki se uporabljajo za tiskanje, vplivajo na kakovost komponent. S 3-D tiskalniki je mogoce natancno, enostavno in prirocno izdelati dele, oblikovanje in tiskanje je hitro in stroškovno ucinkovito in hkrati prilagodljivo najrazlicnejšim uporabam. Bati se izdelujejo z metodo ciljnega nanosa (FDM – Fused Deposition Method) ob uporabi polilakticne kisline (PLA – Poly Lactic Acid). PLA je biorazgradljiva termoplastika, ki se obicajno uporablja za izdelavo prototipov. Gre za plasticni material na rastlinski osnovi, ki je obicajno izdelan iz koruznega škroba. Slika 3 prikazuje dimenzijo, upoštevano pri izdelavi. Najprej je bil dizajn izdelan v programski opremi AutoCAD in nato pretvorjen v datoteko .stl. Simplify 3D je programska oprema za rezanje, ki se uporablja za nadzor vseh vidikov in pretvorbo oblike v navodila, ki jih tiskalnik razume. Podloga je pred tiskom predhodno segreta, uporabljena je šoba s Due to the extensive use of digital technology in a number of applications, Additive Manufacturing (AM) or 3-Dimensional Printing (3DP) has increased in popularity across the world. It is a process of constructing real items from digital information piece by piece, line by line, surface by surface, or layer by layer, utilizing 3-D digital modeling tools and programs. 3-D printing is a type of printing that can construct or recreate freestanding complex structures in a single piece. The size of a 3-D printer, as well as the materials utilized for printing, have an influence on component quality. 3-D printers have the potential to manufacture quality work pieces with precision, ease of use, convenience, rapid design and printing, cheap cost, and the capacity to adapt to a variety of applications. A piston is being fabricated by the Fused Deposition Methods (FDM) method using Poly Lactic Acid (PLA). PLA is a biodegradable thermoplastic that is commonly used to create prototypes. It is a vegetable-based plastic material that commonly uses cornstarch as raw material. Figure 3 shows the dimension considered for fabrication. First, the design was made in AutoCAD and converted into stl file. Simplify 3-D is slicing software used to control every aspect and convert the Preglednica 3. Specifikacija motorja lahkega motornega vozila Table 3. The LMV engine specification Parametri / Parameters Vrednosti / Values Vrsta motorja / Engine type Štiritaktni bencinski motor / Four stroke petrol engine Število valjev / Number of cylinders 3 Odprtina / Bore 68,5 mm Hod / Stroke 72 mm Prostornina / Volume 796 cm3 Najvecja moc / Maximum power 48 KM pri 6000 vrt./min / 48PS@6000 rpm Najvecji navor / Maximum torque 69 Nm pri 3500 vrt./min / 69Nm@ 3500 rpm Kompresijsko razmerje / Compression ratio 10,3:1 Preglednica 4. Konstrukcijski parametri in izracun za bat motorja lahkega motornega vozila Table 4. Design Parameters and Calculation for LMV Engine Piston Specifikacije / Specifications Parametri / Parameters Mere so podane v mm / Dimensions are in mm Debelina glave bata / Thickness of piston head (t) H 4,64 Radialna debelina obroca / Radial thickness of ring (t) 1 2,48 Aksialna debelina obroca / Axial thickness of ring (t) 2 0.7 t do/to t; t= 0,92 t1121 2,28 Debeline zgornje površine nad utorom / Top land thickness (b) 1 t do/to 1,2 tHH 5,57 Debelina površine med utori / Thickness of other land (b) 2 0,75 t do/to t22 1,71 Skupna dolžina bata / Total length of piston 1 do/to 1,5 D 71,93 (1,05 D) Dolžina valja / Barrel length Skupna dolžina bata / Total Length of Piston tH 67,29 Najvecja debelina valja / Maximum thickness of barrel (t) 3 0.03D+b*+4.5 *b=t+ 0.4 1 9,43 Debelina odprtega konca valja (zgoraj) / Open end of barrel thickness 0,20 do/to 0,30 t3 2,36 Razmak med obrocki / Gap between rings (t) L 0,055D 3,76 Globina utora obrocka / Depth of ring groove (D) r t+0,4 1 2,87 Premer bata / Piston pin diameter (P) do 0,3D do/to 0,45D, (0,3D) 20,5 Dolžina plašca bata / Length of piston skirt 0,65 do/to 0,8 D 47,4 Skupna dolžina bata / Total length of piston 1 do/to 1,5D 71,93 (1,05 D) premerom 0,4 mm. Šoba se segreva, da tali plastiko, in je opremljena z mehanizmom, ki omogoca vklop in izklop toka staljene plastike. Ko se šoba premika po mizi glede na zahtevano geometrijo, nanese majhno kolicino ekstrudirane plastike, ki tvori posamezno plast. Koncni natisnjeni izdelek in nastavitev stroja so prikazani na Sliki 6. Sklepi Lahka motorna vozila se pogosto uporabljajo za osebni prevoz in tudi uradne namene, njihova proizvodnja pa se v zadnjih 15 letih v Indiji nenehno povecuje (208 %). Predvideno povecanje proizvodnje lahkih motornih vozil design into the instructions that the printer understood. The base is preheated before printing and used the nozzle diameter 0.4 mm. The nozzle is heated to melt the plastic and has a mechanism which allows the flow of the melted plastic to be turned on and off. As the nozzle is moved over the table in the required geometry, it deposits a thin bead of extruded plastic to form each layer. The final printed product and the machine setup are shown in Figure 6. 5 Conclusions Light motor vehicles are widely utilized for personal transportation and official s 4,24 na 4,71 milijona med letoma 2022 purposes and their production has been in 2025 in proizvodnje do leta 2025, na increasing continuously (208 %) during podlagi cesar izhaja, da se potrebe po batih the last 15 years in India. Forecasted povecujejo s 13,23 na 14,69 milijona. Izbrali LMV production requirement 4.24 to 4.71 smo zahtevno komponento bata za motor million from 2022 to 2025 AD and the piston lahkega motornega vozila in projektirali requirement up to 2025 AD and it is found ulitek bata ter njegove parametre. Razvili that piston requirements are increasing smo inovativno tehnologija 3-D tiskanja za from 13.23 to 14.69 million. Selected a proizvodnjo batov te izdelali prototip bata. complicated component of the piston for LMV engine and designed piston casting and its parameters. Innovative technique of 3-D printing technology developed for piston manufacturing and prototype piston manufactured. Viri / References [1] Report on Automobile Industry in India, Published by India Brand Equity Foundation, 2021, http://www.ibef.org. [2] Road Transport Year Book, Published by Ministry of Road Transport & Highways, Govt. of India, 2017. [3] Report on Auto Industry Sales Performance of August 2021, Published by Society of Indian Automobile Manufacturers. [4] William H. Crouse, Automotive Mechanics, Tata McGraw Hill, 2007, pp 2-3. [5] Suresh Kumar, “Studies on Terotechnology Applications for Indian Automotive Systems” M Tech Thesis Report, 2011, North Eastern Regional Institute of Science and Technology, Arunachal Pradesh, India. [6] Campbell, T., Williams, C., Ivanova, O., and Garrett, B. (2011). “Could 3D Printing Change the World? Technologies, and Implications of Additive Manufacturing” Atlantic Council, [7] R. 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[15] Jadhav Vishal R K Jain., and YS Chouhan., “Designand Analysis of Aluminium Alloy Piston Using CAE Tools” International Journal of Engineering Sciences & Research Technology, ISSN: 2277-9655 July, 2016. [16] Rupshree ozah and Manapuram Muralidhar: “A Study of Technological Innovation of Production of Automotive Piston Casting by 3 D Printing” August, 2021, Published in Archers &Elevators Publishing House , Bangalore, India, pp131-139. J. Brence1, S. Kastelic1,2, A. Mahmutovic2, P. Mrvar3 1Livarna Titan, d.o.o., Slovenija / Slovenia 2TC Livarstvo, Ljubljana, Slovenija / Slovenia 3Univerza v Ljubljani / University of Ljubljana, Naravoslovnotehniška fakulteta / Faculty of Natural Sciences and Engineering, Slovenija / Slovenia Optimizacija ulivno-napajalnega sistema ulitka kape izolatorja iz bele temprane litine Design Optimization of Gating System for Insulator Cap from White-Heart Malleable Iron Povzetek Ulivno-napajalni sistem za vertikalno litje v pešcene forme mora biti dimenzioniran na nacin, da je tok taline cim manj turbulenten, da plini iz pešcene forme in okoliški zrak niso ujeti v toku ter da med litjem ne prihaja do erozije pešcene forme. Talina mora vstopiti v livno votlino na nacin, da povzroci temperaturno razliko, ki spodbuja usmerjeno strjevanje ulitka. Med masovno proizvodnjo se lahko pri litju v pešcene forme pojavijo številne napake, kot so plinska in krcilna poroznost, hladni spoji, vkljucki žlindre, razpoke v vrocem, pripecen pesek, odkrušena forma itd. Racunalniško podprte simulacije litja in strjevanja so dandanes kljucne za optimizacijo parametrov procesa litja ter za predvidevanje možnih napak in tveganj, še preden te nastopijo. Z njimi lahko že v fazi razvoja orodja dolocimo najbolj optimalne pogoje litja in konstruiramo primeren ulivno-napajalni sistem glede na specifikacije ulitka. V tem clanku je opisana optimizacija elementov ulivno-napajalnega sistema kape izolatorja, izdelane iz bele temprane litine. V podjetju Livarna Titan d.o.o. v Kamniku so namrec na tem artiklu beležili velik delež kakovostno neskladnih ulitkov. Korektivni ukrepi so bili izvedeni na podlagi enostavne termicne analize »in situ« in racunalniško podprtih izracunov litja in strjevanja z uporabo programskega paketa ProCAST. Kljucne besede: gravitacijsko litje, ulivno-napajalni sistem, temprana litina, simulacija, ProCAST Abstract The gating system for the vertical sand mold casting process must be dimensioned in such a way that the melt flows through it with as low turbulences as possible, that gases and ambient air are not trapped in the flow and that erosion of the sand mold does not occur during filling. The melt must also enter the casting cavity in a way that promotes directional solidification from the casting’s hot spot through the feeder neck up to the feeder. During mass production, casting defects such as gas and shrinkage porosity, cold shuts, slag inclusion, hot tears, burnt on the sand, mold defects, etc. can occur. Nowadays, computer-aided simulations of filling and solidification are crucial for optimizing the parameters of the casting process and for predicting possible errors and risks before they occur. With them, we can determine the most optimal casting conditions already in the tool development phase and construct a suitable gating system, according to the specifications of the casting. This work describes the gating system optimization of insulator caps, made from white-heart malleable iron. To reduce the large number of scraped castings in the company Livarna Titan, d.o.o. in Kamnik, a change was made to the casting tool based on “in-situ” thermal analysis and computer-aided calculations of filling and solidification using ProCAST simulation software package. Keywords: gravity casting, gating system, malleable iron, simulation, ProCAST 1 Uvod Zasnova ulivno-napajalnega sistema je v proizvodnem procesu vsake livarne kljucnega pomena, saj le-ta neposredno vpliva na izplentaline (razmerje bruto/neto), delež izmeta in s tem tudi na produktivnost proizvodnje. Danes je med podjetji znižanje proizvodnih stroškov kljucni cilj, h kateremu stremijo prav vsa. Visoke cene energentov (elektrika, plin) in vhodnih surovin (jekleni odpad, železove zlitine itd.) ter težave s pridobitvijo ustreznega kadra na trgu dela so vsa podjetja postavile v težek položaj. Livarne morajo zato proizvajati ulitke s cim nižjimi stroški in socasno zagotavljati ustrezno kakovost. Pravilna zasnova ulivno­ napajalnega sistema je zahtevna, a zelo pomembna naloga, zato je že med njegovim nacrtovanjem pomembno zagotoviti, da litina pravocasno in enakomerno zapolni livno votlino. Vse parametre je kljub dolgoletnim izkušnjam težko upoštevati in pravilno oceniti, zato se tudi male in srednje livarne vse pogosteje odlocajo za uporabo racunalniško podprtih izracunov livarskih procesov. Dimenzije ulivnih kanalov je treba izracunati glede na geometrijo izdelka, saj je lahko nepravilna zasnova glavni vzrok za napake, ki jih je mogoce zaznati na površini ali vecinoma v notranjosti ulitkov. Slika 1 prikazuje obstojeci ulivno-napajalni sistem ulitka kape izolatorja z oznacenimi obmocji prisotne krcilne poroznosti. Preiskovan ulitek je kapa izolatorja, ki je sestavni del izolatorja za uporabo na visokonapetostnih daljnovodih. Ti so del prenosnega elektricnega omrežja, 1 Introduction The design of the pouring and feeding system is of key importance in the production process of every foundry, as it directly affects the yield of the melt (gross/ net ratio), the amount of scrap, and thus the productivity of production. Today, the reduction of production costs is a key goal for companies to strive towards, mainly due to the high prices of energy supply (electricity, gas) and input raw materials (steel scrap, ferroalloys, etc.) and problems with obtaining suitable personnel on the labor market. Foundries must therefore produce castings with the lowest possible costs and at the same time ensure the highest quality. The correct design of the gating system is a difficult but very important task. Therefore, already during its planning, it is important to ensure that the cast iron fills the casting cavity in a timely and uniform manner. Despite many years of experience, all parameters are difficult to take into account and correctly evaluate, which is why even small and medium-sized foundries are increasingly choosing to use computer-aided calculations of foundry processes. The dimensions of the casting channels must be calculated according to the geometry of the product since improper design can be the main cause of defects that can be detected on the surface or mostly inside the castings. Figure 1 shows an existing gating system of an insulator cap with marked areas of shrinkage porosity. The investigated casting is an insulator cap, an integral part of an insulator for use Slika 1. Obstojeci ulivno-napajalni sistem z oznacenimi obmocji krcilne poroznosti (a), porušen ulitek z vidno poroznostjo (b) Figure 1. Existing gating system with marked areas of shrinkage porosity (a), casting with visible porosity (b) ki povezuje elektrarne z razdelilnimi transformatorskimi postajami. Izolacijski nosilci oz. izolatorji so potrebni na mestih, kjer so nadzemni vodi pritrjeni na kovinske nosilce. Izolatorji zagotavljajo potrebno izolacijo med vodniki in nosilci ter preprecujejo uhajanje toka iz vodnikov v zemljo. on high-voltage transmission lines. These are part of the transmission power network that connects power plants with distribution transformer stations. Insulation supports or insulators are required in places where overhead linesare attached to metal towers. Insulators provide the necessary insulation 17 kg 20 kg 16,8 kg Slika 2. Potek sprememb ulivno-napajalnega sistema kape izolatorja, izhodišcno stanje (a); prva optimizacija (b), druga optimizacija (c) Figure 2. The course of changes to the gating system of insulator cap; existing (a), first optimization (b), second optimization (c) Slika 2 prikazuje potek optimizacije koncnega ulivno-napajalnega sistema. Pri prvi optimizaciji smo s prestavitvijo lokacije napajalnikov uspešno odpravili krcilno poroznost v ulitku, ampak pri tem povecali bruto težo sistema s 17 kg na 20 kg. V drugem delu optimizacije smo zaradi težnje po dosegu vecjega izplena taline optimizirali obliko napajalnikov na najmanjšo mero, ki še zagotavlja usmerjeno strjevanje. Pri tem smo bruto težo zmanjšali z 20 kg na 16,8 kg in tako povecali izplen taline za 16 %. Ob kapaciteti proizvodnje 200 izdelanih form na uro to pomeni prihranek 4800 kg taline na izmeno. 2 Eksperiment Preiskovani ulitek kape izolatorja je izdelan iz bele temprane litine kakovosti EN-GJMW-550-04 (DIN EN 1562:2019), njegova neto teža je 2,6 kg. Zaradi same geometrije ulitka in želje, da se za izdelavo votlih delov uporabi eno jedro za vec ulitkov, je bil obstojeci ulivno-napajalni sistem konstruiran, kot prikazuje slika 2 a). Izbrani so bili napajalniki cilindricne oblike, ki napajajo ulitek skozi ušesa kape izolatorja. Ta postavitev je ugodna, saj je tako omogoceno brušenje vratu napajalnika po ravni površini. Litje zacetnih vzorcev je bilo realizirano pri temperaturi 1420 °C in kemicni sestavi, podani v Preglednici 1. Tabela 1. Kemicna sestava taline Table 1. Chemical analysis of the melt C Si S Mn Cr [mas. %] 2,83 1,00 0,04 0,85 0,08 Slika 1 b) prikazuje porušen ulitek v litem stanju, kjer je po celotnem preseku between power lines and supports and prevent leakage of current into the ground. Figure 2 shows the flow of optimization of the gating system. In the first optimization, by moving the location of the feeders, we successfully eliminated shrinkage porosity in the casting, but at the same time increased the gross weight of the system from 17 kg to 20 kg. In the second part of the optimization, due to the tendency to achieve better yield , we optimized the shape of the feeders to the smallest possible extent, which still ensures directional solidification. In doing so, we reduced the gross weight from 20 kg to 16,8 kg and thus increased the yield of melt by 16 %. With a production capacity of 200 molds per hour this amounts to 4800 kg less material needed per shift. 2 Experimental The investigated insulator cap casting is made of white-heart malleable cast iron, quality EN-GJMW-550-04 (DIN EN 1562:2019) with a net weight of 2.6 kg. Due to the geometry of the casting and the desire to use one core for two castings for the production of a hollow inside part, the existing gating system was constructed as shown in Figure 2 a). Cylindrical-shaped feeders were chosen that feed the casting through the »ears« of the insulator cap. This arrangement is advantageous, as it enables the feeder neck to be round on a flat surface. The casting of the initial samples was realized at a temperature of 1420 °C and the chemical composition is given in table 1. Figure 1 b) shows casting in an as-cast state, where a crystalline shinecharacteristic of cementite is visible throughout the cross-section, which means that the casting has completely solidified "white" according to the metastable system Fe – Fe3C. During viden kristalni lesk, znacilen za cementit, kar pomeni, da se je ulitek v celoti strdil »belo« po metastabilnem sistemu Fe – Fe3C. Z žarjenjem oz. tempranjem pa ledeburitni (evtektski) Fe3C razpade, pri cemer se ogljik odlaga v obliki kompaktnih delcev, imenovanih temprani ogljik. Da bi bil izracun livarskih procesov kar najbolj natancen, so bili doloceni robni pogoji, eksperimentalno opredeljeni z meritvami temperatur na posameznem mestu ulitka, napajalnika in v pešceni mešanici. Na osnovi eksperimentalno pridobljenih ohlajevalnih (litina) in segrevalnih (pešcena mešanica) krivulj je bila izvedena ponastavitev koeficienta prenosa toplote v odvisnosti od temperature. Meritve temperature so bile izvedene na 6 razlicnih mestih, kot to prikazuje Slika 3. Podatke smo zajemali z analogno-digitalnim pretvornikom proizvajalca National Instruments tip NI9213 in programom Labview. Frekvenca meritev je bila 50 Hz. Uporabljeni so bili termocleni tipa K (Ni – Cr – Ni), oplašceni z inoksom ali steklenimi vlakni. Plašc iz inoksa je bil uporabljen v primeru neposrednega stika s talino. Termoelementi, ki so bili v pešceni mešanici, pa so imeli plašc iz steklenih vlaken. Slika 3. Postavitev termoclenov v pešceni formi Figure 3. Placement of thermocouples in a sand mold heat treatment - tempering, the ledeburite (eutectic) Fe3C breaks down, whereby the carbon is deposited in the form of compact particles called tempered carbon. To make the calculation of the foundry processes as accurate as possible, boundary conditions were experimentally defined by temperature measurements at individual places of the casting, the feeder, and in the sand mixture. Based on the experimentally obtained cooling (casting) and heating (sand mixture) curves, the heat transfer coefficient was reset as a function of temperature. Temperature measurements were made at 6 different places, as shown in Figure 3. Data were collected with an analog-digital converter manufactured by National Instruments, type NI9213, and the Labview program. The measurement frequency was 50 Hz. Thermocouples type K (Ni – Cr – Ni) coated with stainless steel or fiberglass was used. Astainless steel jacket was used where there was direct contact with the melt. The thermocouples, which were in the sand mixture, had a fiberglass jacket. 3 Rezultati Na izrisanem 3-D modelu smo izvedli numericno simulacijo litja in strjevanja. Za geometrije ulitka in ulivno-napajalnega sistema, jeder in pešcene forme smo izdelali površinsko mrežo, ki je sestavljena iz preprostih celic, s katerimi opišemo celotno geometrijo. Natancnost izdelave mreže in izracunane simulacije je odvisna od velikosti površinskih elementov. Izdelano površinsko mrežo predstavlja Slika 5. Na ulitku smo izbrali velikost površinskih elementov 1,5 mm, saj nas je zanimala prisotnost livarskih napak. Za ulivno­ napajalni sistem smo nastavili velikost 2,5 mm in za jedra 5 mm. Pešceno formo smo razdelili na površinske elemente z velikostjo 12 mm. Poleg površinske mreže smo izracunali še volumsko mrežo. Skupno je tako bilo pripravljenih 5.270.162 volumskih elementov. Cas racunanja je znašal 2 h 50 min. Na Sliki 6 je prikazan posnetek simulacije strjevanja v trenutku, ko ulitek izgubi povezavo z napajalnikom. To obmocje v ulitku predstavlja zadnje strjevalno podrocje. Napajalnik ni zmožen zagotavljati zadostne kolicine taline skozi 3 Results Numerical simulation of casting and solidification was carried out on the drawn 3-D model. For the geometries of the casting and gating system, cores, and sand form, a surface mesh grid was created, which consists of simple cells that describe the entire geometry. The accuracy of the mesh creation and the calculated simulation depends on the size of the surface elements. Figure 5 shows the produced surface mesh. The size of the surface elements on the casting was determined at 1.5 mm, as we were interested in the presence of casting defects here. A size of 2.5 mm was chosen for the gating system and 5 mm for the cores. The sand mold was divided into surface elements with a size of 12 mm. After the surface mesh was computed, the volume mesh was created. A total of 5,270,162 volume elements were thus prepared. The calculation time was 2 h 50 min. Figure 6 shows a snapshot of the solidification simulation at the moment when the casting loses its connection with the feeder. This area in the casting thus represents the last solidification area, and since the feeder is not able to provide enough melt throughout the entire solidification time and thus compensate for shrinkage, a high probability of shrinkage porosity can be expected here. The reason for this is that the feeder is designed in such a way that it feeds the casting through the "ears". In doing so, it places a heavy thermal load on the smaller Slika 5. Površinska mreža Figure 5. Surface mesh celoten cas strjevanja in tako kompenzirati krcenja, zato je tukaj pricakovati veliko verjetnost pojava krcilne poroznosti. Vzrok za to je, da je napajalnik konstruiran na nacin, da napaja ulitek skozi »ušesa«. Pri tem mocno toplotno obremeni manjše jedro (Slika 7) in ta del ulitka se zato ohlaja pocasneje. Posledicno ima tukaj ulitek tudi najvecji termalni modul. Ker se ohlaja pocasneje, je cas do temperature solidus na tem delu okoli 270 s, medtem ko se vrat napajalnika strdi po 220 s. Slika 9 prikazuje izracun toplotnega modula za ulitek kape izolatorja. Opaziti je, da je modul na sredini ulitka najvecji, in sicer okoli 0,52 cm, medtem ko je najmanjši modul ulitka 0,28 cm. Modul core (Figure 7) and this part of the casting, therefore, cools more slowly. As a result, the casting here also has the highest thermal modulus. Because it cools more slowly, the time to solidus temperature is around 270 s, while the neck of the feeder solidifies after 220 s. Figure 9 shows the thermal modulus calculation for an insulator cap casting. It can be seen that the module in the middle of the casting is the largest, namely around 0,52 cm, while the smallest module of the casting is 0,28 cm. The modulus of the feeder’s neck varies between 0,44 cm and 0,47 cm, which is not sufficient because the modulus of the feeder’s neck should be greater than the highest modulus of the vratu napajalnika se giblje med 0,44 cm in 0,47 cm, kar pa ni zadostno, saj bi moral biti modul vratu napajalnika vecji od najvišjega modula ulitka, da bi dosegli usmerjeno strjevanje iz ulitka skozi vrat napajalnika v napajalnik. To merilo imenujemo merilo modulov, kjer je MU modul ulitka, MV modul vratu napajalnika in MN modul napajalnika. MU < MV < MN (2) Nov ulivno-napajalni sistem je bil zasnovan na nacin, da smo ohranili postavitev ulitkov na modelni plošci. Tako smo se izognili popravilu orodja za izdelavo jeder in orodja za vlaganje jeder v pešceno formo. Napajalnike smo postavili na del ulitka, ki ga je simulacijska programska oprema ProCAST izracunala kot tistega z najvecjim termalnim modulom in kot obmocje, ki se strdi zadnje. Napajalnike smo prav tako povecali, da bi dovajali dovolj taline v ulitek, tako da je njihov modul vecji kot modul ulitka, katerega napajajo. Rezultati meritev temperatur v ulitku, jedru in pešceni mešanici so podani na Sliki 10 in Sliki 11. S termoclenom 1 smo izmerili maksimalno temperaturo 1419 °C, ki smo jo potrdili tudi s sondo za merjenje temperature na vlivnem avtomatu. S spreminjanjem temperature skozi cas lahko spremljamo ohlajanje taline do konca formarske linije, kjer se ulitki locijo od pešcene mešanice. Takrat smo termoclene odklopili in ulitke pobrali iz forme. Proga, na kateri se ulitki ohlajajo v pešceni mešanici, preden padejo v hladilni boben in se od pešcene mešanice locijo, je dolga 12 m. To pot ulitki dosežejo po 12 minutah, temperatura po tem casu znaša 818 °C. To pomeni, da je hitrost ohlajanja okoli 50 °C/min. Termoclen T2 je bil lociran v sredini napajalnika spodnjega ulitka (zaradi poteka dovodnega kanala termoclenov nismo mogli postaviti v zgornji ulitek). Za okoli 30 s je termoclen izgubil povezavo, vendar se je ta nato vrnila. Opazimo, da temperatura casting to achieve directional solidification from the casting through the feeder’s neck into the feeder. This is called the modulus criterion, where MU is the modulus of the casting, MV is the modulus of the feeder neck, and MN, is the modulus of the feeder. MU < MV < MN (2) The new gating system was designed in such a way as to preserve the placement of the castings on the model plate, as this avoided the repair of the core-making tool and the core setter. We placed the feeders on the part of the casting that ProCAST calculated as having the highest thermal modulus and as the area that solidifies last. We have also enlarged the feeders to feed enough melt into the casting so that their modulus is greater than the modulus of the casting they feed. The results of temperature measurements in the casting, core and sand mixture are given in Figures 11 and Figure 12. With thermocouple 1, the maximum temperature was measured at 1419 °C, which was also confirmed with the temperature measuring probe on the pouring machine. By changing the temperature over time, we can monitor the cooling of the melt to the end of the cooling line, where the castings are separated from the sand mixture. At that time, we disconnected the thermocouples and collected the castings from the mold. The line on which the castings are cooled in the sand mixture before falling into the cooling drum and separating from it is 12 m long. The castings reach this path after 12 min, the temperature after this time is 818 °C. This gives us a cooling rate of around 50 °C/min. Thermocouple T2 was located in the middle of the feeder of the lower casting (due to the flow of the runners, we could not place the thermocouples in the upper casting). For about 30 s, the thermocouple pada pocasneje kot v termoclenu T1. To ni presenetljivo, saj je volumen napajalnika veliko vecji kot volumen razdelilnega kanala, zato se ta ohlaja pocasneje. Maksimalna dosežena temperatura je znašala 1385 °C, in sicer okoli 6 s po zacetku litja, kar se natancno sklada z izracunom litja. Toliko casa je talina potrebovala za pot od livne caše do spodnjega napajalnika. Termoclena T4 in T5 sta merila temperaturo v pešcenem jedru. Izmerjene temperature termoclena T4 so višje, ker je termoclen bližje napajalniku kot termoclen T5. Iz grafa je razvidno, kako se temperatura v jedru povecuje, ko toplota prehaja iz ulitka lost connection, but then it came back. We notice that the temperature drops more slowly than in thermocouple T1. This is not surprising, because the volume of the feeder is much larger than the volume of the runner, so it cools more slowly. The maximum temperature reached was 1385 °C, about 6 s after the start of casting, which is exactly in linewith the casting calculation. That's how long the melt needed to travel from the pouring basin to the lower feeder. Thermocouples T4 and T5 measured the temperature in the sand core. The measured temperatures at T4 are higher because the thermocouple is closer to Slika 12. Primerjava segrevalnih krivulj eksperimenta in simulacije v pešcenem jedru (a), pozicija termoelementa T4 (b), mesto dolocitve izracunane segrevalne krivulje (c) Figure 12. Comparison of the heating curves of the experiment and simulation in the sand core (a), the position of the thermocouple T4 (b), the location of the calculated heating curve (c) na jedro. Opazna pa je tudi sprememba na krivulji T4 in T5, in sicer pri temperaturi okoli 80 °C, kar je skladno s temperaturo vžiga fenolne smole v jedru Croning. Slika 12 prikazuje primerjavo med eksperimentalno doloceno in izracunano segrevalno krivuljo v pešcenem jedru ter položaj termoelementa T4 v pešceni formi in na virtualnem jedru. Opazimo, da je izracunana segrevalna krivulja bolj zvezna, saj ne upošteva vseh pogojev, kot je npr. the feeder than the T5 thermocouple. The graph shows how the temperature in the core increases as heat passes from the casting to the core. A change in the T4 and T5 curve is also noticeable at a temperature of around 80 °C, which would correspond to the ignition temperature of the phenolic resin in the Croning core. Figure 12 shows a comparison between the experimentally determined and calculated heating curve in the sand Figure 15. Calculation of total shrinkage porosity for version 1 (left) and version 3 (right) vžig fenolne smole, kar pa je zaznano na eksperimentalno doloceni krivulji. Zaradi manjših razlik med eksperimentom in izracunom smo v programu ProCAST nekoliko spremenili dolocene parametre jedra Croning (gostota, prevodnost), da smo se cim bolj približali realnemu stanju. Na Sliki 13 lahko vidimo primerjavo izracuna strjevanja za verzijo 1 in verzijo 3 približno 150 s po zacetku litja. Pri verziji 3 s spremenjenim položajem napajalnikov se ulitek strjuje enakomerno v napajalnik in ne izgubi povezave z njim. Prav tako se mesto najvecjega termalnega modula prestavi na obmocje pod napajalnikom. Zaradi tega se zmanjša tudi pregrevanje manjšega jedra (Slika 14). Tako smo dobili usmerjeno strjevanje, ki je najucinkovitejši ukrep za odpravo krcilne poroznosti. Pri usmerjenem strjevanju ni bistvena preprecitev nastanka lunkerja, pac pa njegov prenos na neškodljivo mesto, to je v napajalnik (Slika 15). Zakljucek Pri gravitacijskem litju v pešcene forme je zasnova ulivno-napajalnega sistema izjemno pomembna, saj njegova geometrija neposredno vpliva na kakovost ulitkov in kolicino izmeta. Kljucni cilj ulivnega sistema je zagotoviti nemoten pretok taline iz livne caše v livno votlino celoten cas litja in strjevanja. V clanku je bila opisana sprememba postavitve in geometrije napajalnikov za ulitek kape izolatorja. Na obstojecem ulivno-napajalnem sistemu je bilo po litju zaznati povecan delež livarskih napak, predvsem kot posledica krcilne poroznosti. V sklopu optimizacije so bili napajalniki prestavljeni na mesto, kjer so racunalniški izracuni dolocili najvišji termalni modul in ga prepoznali kot obmocje, ki se strdi zadnje. core and the position of the thermocouple T4 in the sand mold and on the virtual core. We notice that the calculated heating curve is more uniform as it does not take into account all conditions such as e.g. ignition of the phenolic resin, which is detected on the experimentally determined curve. Due to minor differences between the experiment and the calculation, we slightly changed certain parameters of the Croning core (density, conductivity) in the ProCAST program to get as close as possible to the real situation. In Figure 13 we can see a comparison of the solidification calculation for version 1 and version 3 approximately 150 s after the start of casting. In version 3 with a changed position of the feeder, the casting solidifies evenly in the direction of the feeder and does not lose its connection with it. Also, the location of the largest thermal module is moved to the area under the feeder. This is also registered on the temperature field calculation of the sand core (Figure 14). Based on the applied changes, directional solidification was obtained, which is the most effective measure to eliminate shrinkage porosity. It is not essential to prevent the formation of a shrinkage defect, but rather to transfer it to a harmless place, i.e., to the feeder (Figure 15). 4 Conclusions In gravity casting in sand molds, the design of the gating system is extremely important, as its geometry directly affects the quality of the castings and the amount of scrap. The key goal of the gating system is to ensure a smooth flow of melt from the pouring cup to the casting cavity throughout the casting and solidification period. The article described a change in the layout and geometry of the feeders for Rezultati teh izracunov so bili potrjeni s stanjem po litju v proizvodnji. insulator cap casting. On the existing gating system, an increased proportion of casting defects was detected after casting, mainly as a result of shrinkage porosity. As part of the optimization, the feeders were moved to the place where the simulation showed the highest thermal modulus and recognized as the area that solidifies last. The results of these calculations were confirmed with the results after casting in production. 5 Viri in literatura / References [1] DISAMATIC 2013 MK5-ASand Moulding System: Application Manual. Edition 05-94. Denmark: DISA Indstries, 2012, 696 str. [2] Design of Gating and Feeding Systems. Materials and Metallurgical Engineering, vol. 346, 12 str. [3] ERBUL, A., VANLI, A., AKDOGAN, A., DURAKBASA, N. Gating system design and optimization in sand mould casting of cast irons. DAAAM International Scientific Book, 2017, str. 173-190 [4] DUBEY, S., SWAIN, R. S. Numerical investigation on solidification in casting using ProCAST. IOP Conf. Ser.: Mater. Sci. Eng., 2019, vol. 561, 10 str. [5] RIDGEWAY, C., RIPPLINGER, K., GU, C., JI, M. Prediction of location-specific mechanical properties of aluminum casting using a new CA-FEA(cellular automation – finite element analysis) approach. Materials and Design, 2020, vol. 194, 14 str. [6] MENEGATTI, A. Postavitev tehnološko procesnega okna za doseganje usmerjenega strjevanja ulitka grelne plošce iz sive litine z lamelnim grafitom: diplomsko delo. Ljubljana, 2021, 50 str. [7] Cooling and Feeding System Design [online]. FLOW-3D [citirano 4.4.2022]. Dostopno na svetovnem spletu: https://www.flow3d.com/modeling-capabilities/metal-casting-models/coo ling-and-feeding-system-design/. [8] Long-rod insulators [online]. LAPP Insulators [citirano 4.4.2022]. Dostopno na svetovnem spletu: https://www.lappinsulators.com/products/porcelain-insulators/ long-rod-insulators. [9] MOCEK, J., ZYCH, J., CHOJECKI, Y. Study of erosion phenomena in sand moulds poured with cast iron. International Journal of Cast Metals Research, 2004, vol. 17, str. 47-50. AKTUALNO / CURRENT 62nd IFC in Portoroz - Slovenia 30 years membership in WFO Dr. Carsten Kuhlgatz announced “Young researchers scientist Award 2023” Dr. Carsten Kuhlgatz, President of the World Foundry Organization, thanked Mirjam Jan-Blazic and her team for the excellent organization and execution of the 62nd IFC in Portoroz. Knowing that Ms. Jan-Blazic organizes this conference with only two other team members, everyone can only have high regard for this achievement. The leaders of the World Foundry organization (WFO) hope that we will be able to participate in many more conferences in Portoroz. 30 years of membership in WFO On behalf of the Executive Committee and the team of General Secretaries, Kuhlgatz thanked the Slovenian Foundry Society for its 30 years of membership in the WFO. The Slovenian Foundry Association is a very active member in the WFO. A highlight of the cooperation was the World Technical Forum, which took place in 2019 in combination with the 59th IFC in Portoroz. The conferences, which are mainly organized by the member associations, provide an excellent forum for foundry professionals from all over the world with the opportunity for exchange of experience, presentation of new technologies and networking. This is also the main task of the WFO and the WFO Working Groups. In many cases, the new technologies are developed by young scientists and experts. Young scientists and professionals conference What could be more obvious than to organize a conference only for young scientists and professionals from all over the world. These young scientists and professionals are our future. However, WFO will not want to hold this conference in person, but rather in the world-wide-web. For the first time the WFO will use a digital conference platform to organize, execute and follow up this special event. We will develop a webpage for the call of papers, the registration of the attendees and the execution of the conference. The young scientist has to send a video of their presentation. This video will be available at the conference platform for a special period in March or April 2023. Everybody who is registered can watch this video at any time. This will ensure that the presentations can be viewed conveniently on any continent and in any time zone. There will be a chat function for questions. Spontaneous discussion sessions can also be initiated via video or chat. Ajury will ensure that the presentations meet a certain quality standard. The jury will evaluate the presentations and select the 3 best of them. About Dr. Carsten Kuhlgatz Dr. Carsten Kuhlgatz is president of the World foundry Organization 2022 and 2023. He was president of Hüttenes-Albertus for 20 years and most recently the CEO of the global HA Group. Today he is shareholder and president of the holding Albertuswerke GmbH. One of their affiliates is Hüttenes-Albertus und die HA-Group. Young scientists Award 2023 at GIFA - GMTN 2023 in Duesseldorf The best 3 presenter’s will be invited to the GIFA 2023 in Düsseldorf. They have to explain their results and developments at the Meeting Point of the GIFA. There they will receive awarded prizes. But without the help of all responsible Persons in the member associations we will not be successful in getting enough presentations. So please support us and promote this special event in your member associations, universities, research institutes and companies. Kuhlgatz is convinced that this format will be a complete success. Subsequently, this platform can be used by all member associations to organize and hold events on behalf of the WFO for a small fee. Editor’s comment: Presented in this article are Dr. Carsten Kuhlgatz’s valuable thoughts, which he gave in his speech on Foundrymen’s night on 15th September 2022. AKTUALNO / CURRENT 62. IFC Portorož 2022 Tradicionalna vsakoletna septembrska livarska konferencaz livarsko razstavo v Portorožu, 62. po vrsti, ki jo organizira Društvo livarjev Slovenije skupajz soorganizatorji: Naravoslovno tehniška fakulteta Univerze v Ljubljani in Fakulteta za strojništvo Univerze v Mariboru, je potekala letos v casu od 14. - 16. septembra. Za razliko od prejšnjih dveh konferenc, ki sta bili organizirani tudi v letih 2020 in 2021, t.j. v letih pandemije korona virusa, je letošnja konferenca potekala brez omejitev in v nadvse sprošcenem vzdušju. Na vsakem koraku se je cutilo veliko zadovoljstvo s tem, da so zopet možni socialni strokovni kontakti v živo. Udeleženci konference in razstave so se na predvecer konference srecali na že tradicionalnem pozdravno-spoznavnem srecanju v Piranu, katerega se zmeraj udeleži tudi predstavnik županstva Obcine Piran. Letos je pozdravne besede udeležencem namenila podžupanja Obcine Piran, ga. Manuela Rojec. Na konferenci so bili prisotni ugledni predstavniki znanstvenih in gospodarskih subjektov iz tujine in Slovenije s podrocja livarske znanosti in stroke ter predstavniki nacionalnih livarskih združenj in društev. Generalna ocena pa je tudi ta, da konferenca ohranja sloves ene od najvecjih livarskih konferenc v tem delu Evrope. Letošnja udeležba z vec kot 290 udeleženci iz 23 držav, vkljucno s Slovenijo, to potrjuje. Na konferenci je bilo predstavljeno preko 40 predavanj, od tega 11 kot plenarna, tri plakatna, ostala pa so bila porazdeljena v sekcije: Lito železo in livarska tehnologija, Neželezove zlitine in Sekundarna oprema in Prizorišce pred razstavnimi dvoranami tehnologije za livarstvo. Predavanja so zajela zelo široko problematiko: razlicne in nove livarske tehnologije ter nove livne materiale, digitalizacijo procesov v industriji 4.0, uporabo industrijskih robotov in novih rešitev za talilne peci in cišcenje ulitkov. Predsednica Društva livarjev Slovenije in predsednica organizacijskega odbora 62. IFC Portorož 2022, mag. Mirjam Jan-Blažic, je na otvoritvi konference in razstave v otvoritvenem govoru podala ugotovitev, da so po pandemiji v ospredje prišle bistveno hitreje nekatere nove teme in rešitve na podrocjih digitalizacije, krožnega gospodarstva in širše trajnostnega razvoja v luci prehoda na zeleno in brezogljicno družbo. Poudarila je, da se po dveh kriznih letih in tudi zaradi vojne v Ukrajini v livarstvu ter celotnem gospodarstvu vse evropske države srecujejo z zelo resnimi problemi in zahtevnimi izzivi, ki se nanašajo na enormno rast cen energentov in preskrbo ter rast cen surovin. Gre za probleme, ki že marsikje vplivajo na zmanjšanje livarske proizvodnje in tudi že ogrožajo obstoj nekaterih podjetij. Zato so udeleženci bili edini, da je za ohranjanje proizvodnje ter delovnih mest, potrebna takojšnja državna pomoc vlad in enotni ter hitri ukrepi tudi na nivoju Evropske Unije in dosleden znan program vladne pomoci že letos tudi za celo naslednje leto. Vsa posredovana predavanja na konferenci bodo s strani predsednika programsko znanstvenega odbora, zasl. prof. dr. Alojza Križmana, predstavljena s kratkimi izvlecki oz. komentarji v locenem prispevku, ki bo objavljen v 4. št. Livarskega vestnika decembra 2022. Na letošnji livarski razstavi v Portorožu je sodelovalo 48 razstavljavcev (od tega 21 iz tujine in 27 iz Slovenije), ki so po vecini dobavitelji razlicnih materialov, opreme ali znanja za livarsko industrijo. Na straneh 188 – 191 te izdaje LV objavljamo fotografije razstavnih prostorov vseh razstavljavcev. Predsednica Organizacijskega odbora 62. IFC Portorož 2022, Mag. Mirjam Jan-Blažic AKTUALNO / CURRENT Društvo livarjev Slovenije ima novega castnega clana Obcni zbor Društva livarjev Slovenije (v nadaljevanju Društvo) je na svoji izredni seji dne 31. 08. 2022, na predlog Izvršnega odbora Društva, sprejel naslednji sklep: Za castnega clana Društva livarje Slovenije se imenuje dolgoletni stanovski kolega iz poljskega združenja livarjev - STOPiz Krakowa, mag. Tadeusz Franaszek. Listina castnega clana mu je slovesno vrocena s strani predsednice Društva in predsednice Organizacijskega odbora IFC, mag. Mirjam Jan-Blažic in predsednika Programsko-znanstvenega odbora IFC, zasl. prof. dr. Alojza Križmana, na otvoritvi 62. IFC Portorož 2022. Mag. Tadeusz Franaszek že od 70 let prejšnjega stoletja ohranja tesne stike z Društvom livarjev Slovenije. V obdobju vec kot 30 let je pogosti udeleženec mednarodne livarske konference v Portorožu, pri cemer je bil skupaj s pokojnim profesorjem Jozefom Suchyjem z Univerze v Krakowu glavni promotor in ambasador povezovanja in sodelovanja. Nenehno je skrbel za ohranjanje in rast sodelovanja z Univerzo v Krakowu ter udeležbo poljskih znanstvenikov kot predavateljev na mednarodni livarski konferenci v Portorožu. V zadnjem desetletju je spodbujal tudi udeležbo predstavnikov poljske livarske industrije za sodelovanje na tem osrednjem vsakoletnem livarskem dogodku Društva. Življenjepis mag. Tadeusza Franaszeka izpricuje njegovo dolgoletno predanost livarstvu na širokem delovnem podrocju: Inštitutsko delo, konstruktorsko in projektantsko delo na podrocju livarskih strojev in opreme, delo na razlicnih projektih uvajanja novih tehnologij v obstojecih poljskih livarnah kot tudi v tujini ter prevzemanje vodstvenih in najvišjih vodilnih funkcij. Posebno dejaven je bil tudi po vseh podrocjih nekdanje Jugoslavije, kjer je denimo poskrbel za zagon livarn v Slavonski Požegi na Hrvaškem, RTB Bor in 14. oktober Kruševac v Srbiji, v podjetju Novi život Zenica v BIH ter celo v Sloveniji v Livarni Titan, Kamnik. Od leta 2007 do danes je glavni urednik poljske livarske revije PRZEGLAD ODLEWNICTWA. Od leta 1951 je clan poljskega združenja livarjev STOP in do današnjih dni je dolgoletni clan njegovega vodstva. Od 2011 do danes pa je predsednik ZG STOP. Mag. Mirjam Jan-Blažic DRUŠTVO LIVARJEV SLOVENIJE Vabilo za 63. IFC PORTOROŽ 2023 z livarsko razstavo 13. - 15. SEPTEMBER 2023 Kontakt: DRUŠTVO LIVARJEV SLOVENIJE, Lepi pot 6, p.p. 424, 1001 Ljubljana T: +386 1 2522 488 drustvo.livarjev@siol.net, www.drustvo-livarjev.si AKTUALNO / CURRENT Galerija slik vseh sponzorjev-razstavljavcev na 62. IFC Portorož 2022 ABC MAZIVA d.o.o. (SI) BENTOPRODUCT d.o.o. (BIH) CARL ZEISS d.o.o. (SI) COLD JET bvba (BE) ELKEM ASA (NO) EXOTERM-IT d.o.o. (SI) FANUC ADRIA d.o.o. (SI) HAGI GmbH (D) HA ITALIA - CHEMEX (I) INDUCTOTHERM EUROPE Ltd. LABTIM d.o.o. (SI) (UK) LAEMPE MÖSSNER SINTO LIVING d.o.o. (SI) MASCHINENFABRIK GUSTAV GmbH (D) EIRICH GmbH & CoKG OLMA d.o.o. (SI) OTTO JUNKER GmbH (D) PCS d.o.o. (SI) PS d.o.o. LOGATEC (SI) PSR d.o.o. (SI) PRIMAKEM d.o.o. (SI) RWP GmbH (D) STEM d.o.o. (SI) SIAPRO d.o.o. (SI) TERMIT d.d. (SI) WEILER ABRASIVES d.o.o. (SI) Galerija slik vseh razstavljavcev na 62. IFC Portorož 2022 AVL LIST GmbH (A) BL METAL, Bogdan Lovšin s.p. (SI) FEAL-INŽENIRING d.o.o. (SI) FPT-LIV d.o.o. (SI) GIESSEREI + HOME OF FOUNDRY (D) IDEF d.o.o. (CRO) INDEMAK Indüksiyon Makinalari Limited Sirketi (TR) IRT 3000 (SI) MAZZON S.p.A. MEREL d.o.o. (SI) Naravoslovnotehniška fakulteta NOVACAST SYSTEMS AB (SE) SIJ RAVNE SYSTEMS d.o.o. (SI) (SI) STEELBERRY s.r.o. (SK) TCTTesic GmbH (D) TOPOMATIKA d.o.o. (SI) TROKU TEST d.o.o. (CRO) WINOAABRASIV MUTA d.o.o. (SI) AKTUALNO / CURRENT Pregled livarskih prireditev v letu 2022 / 2023 Datum dogodka Ime dogodka Mesto in država 05. – 07. 10. 2022 Evropska konferenca tlacnega litja cinka Koblenz, Nemcija 06. – 07. 10. 2022 Randhofenski dan lahkih kovin Salzburg, Avstrija 16. - 20. 10. 2022 74. svetovni livarski kongres in generalna skupšcina WFO Busan, J. Korea 27. - 28. 10. 2022 Ledebur-Kolokvium Freiberg, Nemcija 12. - 16. 06. 2023 Mednarodni sejem metalurgije in livarstva (GIFA) Duesseldorf, Nemcija Livarski vestnik, letnik 69, št. 3/2022 ZLATA POKROVITELJA 62. IFC PORTOROŽ 2022 FULL-SERVICE SUPPLIER OF PRODUCTS AND SERVICES FOR CORE MAKING CORE SHOOTERS GASSING UNITS SAND MIXERS AUTOMATION AUTOMATED VISUAL INSPECTION SPARE PARTS SERVICES ENGINEERING SREBRNA POKROVITELJA 62. IFC PORTOROŽ 2022 MAGMASOFT® THE DIGITAL FOUNDRY PROCESS BRONASTI POKROVITELJI 62. IFC PORTOROŽ 2022 Spektrometeri za analizo kovin Pospešite proizvodni proces in skrajšajte cas med šaržami s Hitachi High-Tech opticnimi emisijskimi spektrometri. Natancna orodja, bodo zagotovila, da so v talini prave sestavine, tako da lahko hitro dosežete izjemne rezultate.Oglejte si ponudbo OES na www.merel.si www.termit.si