The dynamic and static softening behaviors during multistage hot deformation of aluminum alloys have been studied by double-hit compression testing in the temperature range of 300-400 ºC. The interrupted deformations were conducted with delay times varying between 30 and 120 seconds after achieving a strain of approximately 0.4 in the first stage. It was indicated that the considerable dynamic softening and exceptional softening associated with a structure softening exist in alloy deformation at 400 ºC, leading to an initial flow stress value at the second deformation lower than that at the first deformation. For all alloys studied, the static softening increases with increasing deformation temperature and holding temperature and delay times.

Keywords