Stress corrosion cracking of AZ61 magnesium alloy friction stir weldments in ASTM D1384 solution

Abstract

Stress corrosion cracking (SCC) behaviour of a wrought magnesium alloy (AZ61) friction stir weldment was assessed in ASTM D1384 test solution at two strain rates. The analyses have shown that both the parent and the weldment are susceptible to SCC at a nominal strain rate of 10^–6 s^–1. Fractographic evidence clearly reveals the susceptibility, especially of the fine grained region of the friction stir weld nugget to SCC. The susceptibility to cracking has been observed to increase with decreasing strain rate and under this condition (10^–7 s^–1), the behaviour of the parent and the friction stir weldment were nearly the same.