Effect of strain path changes on strain hardening of 6082 aluminium alloy

The effect of strain path changes on the plastic behaviour of 6082 aluminium alloy in four different heat treated conditions has been studied. Sequential compression tests showed that the effects of changes in strain path depends on the initial microstructure, the angle of change in strain path, and the prestrain magnitude. A delay between the two stages of deformation, typical of that involved in sequential tensile tests, also had a significant effect in solution treated and naturally aged material. Without that delay the transient reduction in strain hardening was severe in the solution treated condition and the reduction in strain hardening was much more pronounced in the naturally aged condition. It could inhibit the transient completely in case of a severe prolonged delay with the solution treated condition. Deformation microstructures following different strain paths were observed using TEM for a discussion of the microstructural mechanisms of the strain hardening behaviour.