2018 Volume 59 Issue 11 Pages 1701-1705
In this study, the effects of impurities and processing conditions on the thermal stability of substructures formed via hot deformation were investigated using a plane strain compression (PSC) test. Two types of Al–1%Mn alloys were prepared. One of the alloys had a low content of silicon and iron owing to the use of pure aluminum bare metal (4N–1Mn alloy). The other was cast by using A1050 alloy (1050–1Mn alloy). The PSC tests were performed between 300 and 500°C and were followed by annealing at 500°C for 120 s in a salt bath. After the salt bath treatment, the 4N–1Mn alloys exhibited a recrystallized structure, whereas the 1050–1Mn alloys retained their fiber structure. Although the 4N–1Mn alloys exhibited a small increase in conductivity after the PSC test, the conductivity of the 1050–1Mn alloys showed an apparent increase. The synchrotron radiation analysis confirmed Al–Mn–Si precipitations in the compressed 1050–1Mn alloys. These precipitations could be the reason for the change in conductivity in the compressed 1050–1Mn alloys. Precipitations were barely observed for the compressed 4N–1Mn alloys, and small precipitations formed during hot deformation seemed to affect the formation of the thermal stabilized substructures. In addition, the study results showed that impurities, such as silicon, contribute to precipitation during hot deformation.