Stress Corrosion Cracking Behavior of Fine-Grained AZ61 Magnesium Alloys Processed by Equal-Channel Angular Pressing

The effect of equal-channel angular pressing (ECAP) on stress corrosion cracking (SCC) behavior of a cast AZ61 Mg alloy was investigated in distilled water (DW) using the slow strain rate tensile test (SSRT) at a strain rate of 1 x 10(-6) s(-1). The fine-grained alloy after ECAP showed a greater SCC susceptibility but a higher ultimate tensile strength, compared with the as-cast counterpart. The results were attributed to refined grains, high-density dislocations and increased proportion of high-angle grain boundaries induced by severe plastic deformation, as well as isolated fine beta-phase particles transiting from net-like beta-phase.