30 KB615 KB27 KB200020242012Bajic, NikolaPerović, Milenko A.Radović, NenadRakin, MarkoSedmak, AleksandarVeljić, Darkoštevilka:3letnik:46str. 215-221ISSN:1580-2949COBISSID:933290URN:URN:NBN:SI:doc-Y4LKQVJEenInštitut za kovinske materiale in tehnologijeMateriali in tehnologijefaza taljenjaforcefriction-stir weldingmechanical testmehanski preizkusimetallographymetalografijanumerical simulationnumerična simulacijaplinge stagesilatemperaturatemperaturevarilni parametrivrtilno torno varjenjewelding parametersFriction-stir welding of high-strength aluminium alloys and a numerical simulation of the plunge stage| Vrtilno torno varjenje visokotrdnih aluminijevih zlitin in numerična simulacija faze taljenja|This paper defines a set of welding parameters for the Friction-Stir Welding (FSW) of two forged panels of the alloy EN AW 7049A in a T652 temper and discusses the plunge stage of FSW using numerical modeling. This multi-component aluminum alloy is characterized by high strength, reduced plasticity and poor weldability. Observations of the macrostructure and microstructure clearly showed typical zones of a FSW joint and the appropriate grain sizes. The finest grains were observed within the nugget, while the coarsest grains are found to be in the HAZ. The ultimate tensile strength is 80.3 % of the parent material. A coupled thermo-mechanical model was developed to study the temperature fields and the plunge force of the alloy EN AW 7049A under different rotating speeds, (300, 400 and 500) r/min, during the FSW process of the plunge stage. A three-dimensional FE model has been developed in ABAQUS/Explicit using the arbitrary Lagrangian-Eulerian formulation, the Johnson-Cook material law and Coulombćs Law of Friction. Numerical results indicate that the maximum temperature in the FSW process canbe increased with an increase in the rotational speed, which can be used toreduce the plunge forceV članku je opisana vrsta parametrov za vrtilno torno varjenje (FSW) dveh kovanih panelov iz zlitine EN AW 7049A, popuščene po T652, in talilna faza FSWz uporabo numeričnega modeliranja. Za to večkomponentno aluminijevo zlitino so značilne visoka trdnost, majhna plastičnost in slaba varivost. Opazovanja makro- in mikrostrukture so jasno pokazala tipične cone FSW-spoja in ustrezne velikosti zrn. Raztržna trdnost je pri 80,3 % trdnosti osnovnega materiala. Povezan termomehanski model je bil razvit za raziskovanje temperaturnih polj in silo taljenja EN AW 7049A-zlitine pri različnih hitrosti vrtenja (300, 400 in 500) r/min med vrtilnim tornim varjenjem za talilno fazo FSW-procesa. Tridimenzionalni FE-model je bil razvit v ABAQUS/Explicit z uporabo arbitrarne Lagrange-Eulerjeve formulacije, Johnson-Cookovih zakonov o materialu in Coulombovega zakona o trenju. Numerični rezultati kažejo, da se lahko najvišja temperatura pri FSW-procesu poviša s povečanjem hitrosti vrtenja, ki lahko zmanjša silo potopaTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije