Hot deformation behavior of AA7085 aluminum alloy during isothermal compression at elevated temperature

The isothermal deformation compression tests of AA7085 aluminum alloy were performed on Gleeble1500 system in the temperature range from 250 degrees C to 450 degrees C and at strain rate range from 0.01 s(-1) to 10 s(-1). The microstructure of samples was observed using optical microscopy (OM) and transmission electron microscopy (TEM) techniques. The results show that the peak stress levels decreased with the increase of deformation temperatures or the decrease of strain rate, which can be represented by the Zener-Hollomon parameter in the exponent-type equation with the hot deformation activation energy of 249.11 KJ/mol. Dynamic recrystallization more obviously occurred in the sample with higher Z value than in the sample with lower Z value. Dynamic recrystallization is sensitively dependent on the deformation temperature. (C) 2013 Elsevier B.V. All rights reserved.