Low cycle fatigue behaviour of Al-Mg-Si alloy AA6061 processed by equal channel angular pressing

The low cycle fatigue (LCF) behaviour of aluminium-magnesium-silicon alloy AA6061 processed by equal channel angular pressing (ECAP) was studied. Solutionized specimens of the alloy were subjected to one, two and three passes of ECAP at room temperature using route Bc. Compared to the values of the solutionized material an overall increase in yield strength and ultimate tensile strength with decrease in % elongation is observed for the ECAP processed material. While the solutionized material exhibits cyclic hardening at all strain levels, the ECAP processed material shows different behaviour depending on the number of passes - stable response/cyclic softening/softening followed by hardening. The ECAP processed material after three passes exhibit superior LCF lives at low strains presumably due to higher strength and large refinement of grains. © (2012) Trans Tech Publications.