25 KB87 KB22 KB199219991998Chiarmetta, GianluigiKevorkijan, VaružanŠuštaršič, BorivojTorkar, Matjažletnik:32številka:6str. 539-543ISSN:1318-0010COBISSID:94378URN:URN:NBN:SI:doc-UBIJ6DQCenInštitut za kovinske materiale in tehnologijeŽelezarna JeseniceŽelezarna RavneŽelezarna ŠtoreKovine zlitine tehnologijealuminijaluminumkompozitimehanske lastnostizlitinežlindraPreparation of Al based composite reinforced with fine dross particles| Pridobivanje kompozitov na osnovi aluminija, diskontinuirano ojačanih z delci aluminijeve žlindre|In the casting-house aluminium dross represents a permanent source of waste generation, especially on the end of secondary dross processing, when a fine, low metal content dust, consisting mostly of ?$Al_2O_3$? phase, is usually generated by tumbling. In the present work, this finely powdered by-product was employed as a low cost reinforcement in discontinuously reinforced aluminium matrix composites. By using the fine (less than 50 ?$\mu$?m) fraction of non-metallic particles generated during aluminium dross treatament and part of the in-house recovered aluminium alloy (A 380), low cost aluminium dross metal matrix composites (AlDMMCs) were routinely produced by the conventional squeeze casting technique and the pressure infiltration. The tensile strength and the haradness properties of up to 20 vol.% fine dross particles in AlDMMC were examined. Special attention was paid to the intrinsic economy of the overall process in order to develope a real low cost metall matrix composite suitable for applications in the automotive industry. It was also demonstrated that AlDMMCs can be easily separated into their two constituent parts, the matarix alloy and the dross particles, by simply re-melting and dross treatment. The ability of AlDMMCs to be recycled in a cost effective way can additionally initiate large tonnage applications for these materials in the automotive sector. In this way, the procedure applied can lead to the production of MMCs at a lower cost per kg than the price of (even recycled) aluminium alloys, as a result of extremely low price of the filler. The initial results also suggest that the fine fraction of aluminium dross particles is a promising filler for light and wear resistant automotive partsV delu je opisana uporaba ciklonske frakcije delcev aluminijeve žlindre, sestavljene pretežno iz ?$Al_2O_3$? (s povprečno velikostjo delcev pod 50 ?$\mu$?m) kot ojačitvene faze za pripravo diskontinuirano ojačanih kompozitov na osnovi regenerirane aluminijeve zlitine A-380. Regenerirano zlitino smo pridobili s stiskanjem posnemkov iz sekundarnega litja v Altek-ovi stiskalni napravi. Vzorec kompozita smo izdelali s tlačnim vlivanjem z vtiskanjem in s tlačno infiltracijo prahu žlindre v tovarni Stampal S.p.A., kjer omenjeni tehnolohiji uporabljajo v redni proizvodnji avtomobilskih delov. V nadaljevanju smo, poleg običajnih metalografskih raziskav, določlili trdnost in trdoto vzorcev kompozita, ojačanih z 20 vol.% delcev žlindre. Posebno pozornost smo namenili ekonomski evalvaciji predlagane tehnologije ojačitve regeneriranih aluminijevih zlitin. Ekonomska analiza je pokazala, da so regenerirane aluminijeve zlitine, ojačene z delci žlindre, cenejše od aluminijevih zlitin, kar velja tudi za avtomobilske komponente, pripravljene s tehnologijo tlačne infiltracije. Poleg tega smo ugotovili, da uporaba finih delcev aluminijeve žlindre omogoča zelo enostavno recikliranje obrabljenih izdelkov s ponovnim pretaljevanjem in iztiskanjem Al taline iz nekovinskega ostanka na Altek-ovi stiskalni napravi. Zaradi svoje ugodne cene in možnosti učinkovitega recikliranja je ojačitev regeneriranih aluminijevih zlitin s ciklonsko frakcijo delcev žlindre vsekakor zanimiva za pripravo zelo lahkih, mehansko manj obremenjenih avtomobilskih delov, ki so v prvi vrsti izpostavljeni abrazijiNadaljuje se kot: Materiali in tehnologijeTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije