20.500.12556/RUL-188923 Preoblikovalne lastnosti iztiskane aluminijeve zlitine skupine 7xxx za kovanje diplomsko delo Formability of 7xxx Series Extruded Aluminium Alloy for Forging diploma work V diplomskem delu smo raziskali odziv aluminijeve zlitine EN AW-7049A pri deformaciji v vročem. Preizkušanci so bili izdelani iz iztisnjenega materiala. Namen dela je bil ugotoviti, kako temperatura in hitrost deformacije vplivata na napetost tečenja ter določiti pogoje za nadaljnje procese vroče predelave, predvsem s kovanjem. Kemijsko sestavo smo povzeli iz analize uporabljene šarže, termično obnašanje zlitine pa smo preverili z diferenčno vrstično kalorimetrijo (DSC). Tlačne preizkuse smo izvedli na simulatorju Gleeble 3500P pri temperaturah deformacije 300, 350, 400 in 450 °C, ter hitrostih deformacije 0,01, 0,1, 1 in 10 s⁻¹. Izvedli smo 16 tlačnih preizkusov z različnimi kombinacijami temperature in hitrosti deformacije. Uporabili smo valjaste preizkušance s premerom 10 mm in višino 15 mm. Segrevali smo jih s hitrostjo 3 °C/s, jih pri izbrani temperaturi zadržali 180 s in nato deformirali do končne absolutne prave deformacije |ε| = 1. Rezultati so pokazali, da se z višanjem temperature napetost tečenja zmanjšuje, z večanjem hitrosti deformacije pa povečuje. Največja absolutna vrednost prave napetosti je znašala približno 184 MPa pri temperaturi deformacije 300 °C in hitrosti deformacije 10 s⁻¹, najmanjša pa približno 36 MPa pri temperaturi 450 °C in hitrosti deformacije 0,01 s⁻¹. Za nadaljnje procese vroče predelave, kot je kovanje bi bilo smiselno preveriti temperature deformacije med 400 in 450 °C ter hitrosti deformacije od 0,1 do 1 s⁻¹. Krivulje tečenja niso bile korigirane zaradi trenja v stiku z orodjem in posledičnega sodčkanja vzorce, ter generirane toplote zaradi deformacije in segrevanja med deformacijo, zato smo jih uporabili predvsem za primerjavo posameznih termomehanskih pogojev. This diploma thesis investigated the response of the EN AW-7049A aluminum alloy during hot deformation. The specimens were produced from extruded material. The aim of the work was to determine how deformation temperature and strain rate affect the flow stress and to determine conditions for further hot-working processes, mainly forging. The chemical composition was obtained from the analysis of the investigated batch, while the thermal behavior of the alloy was examined by differential scanning calorimetry (DSC). Compression tests were carried out on a Gleeble 3500P thermomechanical simulator at deformation temperatures of 300, 350, 400, and 450 °C and strain rates of 0.01, 0.1, 1, and 10 s⁻¹. A total of 16 compression tests were performed using different combinations of deformation temperature and strain rate. Cylindrical specimens with a diameter of 10 mm and a height of 15 mm were used. The specimens were heated at a rate of 3 °C/s, held at the selected temperature for 180 s, and then deformed to a final absolute true strain of |ε| = 1. The results showed that the flow stress decreased with increasing temperature and increased with increasing strain rate. The highest absolute value of true stress was approximately 184 MPa at a deformation temperature of 300 °C and a strain rate of 10 s⁻¹, while the lowest was approximately 36 MPa at 450 °C and 0.01 s⁻¹. For further hot-working processes, such as forging, it would be reasonable to investigate deformation temperatures between 400 and 450 °C and strain rates from 0.1 to 1 s⁻¹. The flow curves were not corrected for friction at the tool–specimen interface and the resulting barreling of the specimens, or for heat generated during deformation and the resulting deformation heating. Therefore, they were used mainly for comparison of the individual thermomechanical conditions. aluminijeva zlitina EN AW-7049A deformacija v vročem kovanje tlačni preizkus krivulje tečenja Gleeble 3500P EN AW-7049A aluminum alloy hot deformation forging compression test flow curves Gleeble 3500P true false false Ž. Erker Slovenski jezik Angleški jezik Diplomsko delo/naloga 2026-09-30 09:00:45 2026-09-30 09:00:46 2026-10-06 08:21:01 0000-00-00 00:00:00 2026 0 Ljubljana 0 Ljubljana XII, 27 f. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 669 118044 293774083 31723.pdf 31723.pdf 1 5D657FB7DDC2FCA3080940508FB0065A ee7e174d8cade97f3d7cb4cb0f1631dd0b9db02c90700aaecf4569971060ad38 91f12c32-bc9c-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=249312 Naravoslovnotehniška fakulteta 0 0 0