20.500.12556/RUL-189078 Vpliv hitrosti ohlajanja po homogenizacijskem žarjenju na preoblikovalnost Al zlitine EN AW 6110A diplomsko delo Effect of cooling rate after homogenization annealing on formability Al alloy EN AW 6110A diploma work V diplomskem delu smo preučevali vpliv hitrosti ohlajanja po homogenizacijskem žarjenju na obnašanje aluminijeve zlitine EN AW-6110A pri deformaciji v vročem. Primerjali smo začetno lito stanje ter tri homogenizirana stanja, ohlajena z različnimi hitrostmi hlajenja. Na hitrost hlajenja smo vplivali z različnimi načini hlajenja, kjer smo uporabili hlajenje s turbo hlajenjem z ventilatorji, počasi na zraku in z vodno prho. Iz posameznega homogeniziranega stanja smo pripravili po dva preizkušanca. Preizkuse deformacije v vročem smo izvedli na termomehanskem simulatorju Gleeble 3500 pri dveh temperaturah 390 in 440 °C. Ti temperaturi predstavljata najnižjo in najvišjo temperaturo industrijskega iztiskavanja. Po preizkusih deformacije v vročem smo vzorce vzdolžno prerezali, metalografsko pripravili in pregledali s svetlobnim optičnim mikroskopom. Pri obeh temperaturah deformacije je vzorec z začetnim litim stanjem dosegel največjo napetost tečenja. Pri temperaturi 390 °C je ta znašala približno 129 MPa, pri temperaturi 440 °C pa približno 108 MPa. Med homogeniziranimi stanji je bila pri temperaturi 390 °C najnižja vrednost največje napetosti tečenja izmerjena pri vzorcu s počasnim ohlajanjem na zraku, približno 88 MPa. Pri temperaturi 440 °C je bila najnižja pri vzorcu hlajenem z vodno prho in je znašala približno 72 MPa. Razlike med posameznimi stanji so bile vidne tudi na svetlobni optični mikroskopiji metalografije. Ker vrste in deleža sekundarnih faz nismo določali, njihovega vpliva na izmerjene napetosti nismo mogli neposredno potrditi. Pri vsakem pogoju smo izvedli samo en tlačni preizkus, zato rezultatov nismo statistično ovrednotili in smo jih obravnavali predvsem primerjalno. In this diploma thesis, we investigated the effect of cooling rate after homogenization annealing on the hot-deformation behaviour of the EN AW-6110A aluminium alloy. The initial as-cast condition was compared with three homogenized conditions subjected to different cooling rates. The cooling rate was varied by applying turbo fan cooling, slow air cooling, and water-spray cooling. Two specimens were prepared from each homogenized condition. Hot-deformation tests were carried out using a Gleeble 3500 thermomechanical simulator at two temperatures, 390 and 440 °C. These temperatures represent the lowest and highest material temperatures during industrial extrusion. After hot-deformation testing, the specimens were longitudinally sectioned, metallographically prepared, and examined using an optical light microscope. At both deformation temperatures, the specimen in the initial as-cast condition exhibited the highest flow stress. At 390 °C, the maximum flow stress was approximately 129 MPa, whereas at 440 °C it was approximately 108 MPa. Among the homogenized conditions, the lowest maximum flow stress at 390 °C was measured for the specimen subjected to slow air cooling and was approximately 88 MPa. At 440 °C, the lowest value was measured for the water-spray-cooled specimen and was approximately 72 MPa. Differences between the individual conditions were also observed in the optical micrographs. Since the type and fraction of secondary phases were not determined, their influence on the measured flow stresses could not be directly confirmed. Only one compression test was performed for each condition; therefore, the results were not statistically evaluated and were treated primarily as comparative results. EN AW-6110A homogenizacijsko žarjenje ohlajanje vroča deformacija Gleeble mikrostruktura EN AW-6110A homogenization annealing cooling hot deformation Gleeble microstructure true false false Ž. Košir Slovenski jezik Angleški jezik Diplomsko delo/naloga 2026-10-01 09:00:11 2026-10-01 09:00:34 2026-10-07 09:22:21 0000-00-00 00:00:00 2026 0 Ljubljana 0 Ljubljana XIII, 26 f. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 669 118137 293975043 31905.pdf 31905.pdf 1 7ECB3F2530528A654EB9F165A1023A4B 6d9147e7036c09ce70a3c45939624eaa73544acaf817024fbaf409877edc87db b114053e-bd65-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=249526 Naravoslovnotehniška fakulteta 0 0 0