Microstructure, texture, and mechanical properties of Mg and its alloy during grain growth

Abstract

In the present study, the microstructure, texture and mechanical properties pure Mg and AME300 Mg alloy, i.e. Mg–3 wt.% Al–0.3 wt.% Mn–0.2 wt.% Ce, have been investigated. Hot rolled plates of pure Mg and AME300 Mg alloy were subjected to annealing at temperatures of 150 – 450 C for time periods of 1 min to 1 day. A clear abnormal growth of grains were observed during annealing of pure Mg. However, such abnormality in grain growth behavior was observed in AME300 Mg alloy only at high annealing temperatures of above 400 C. A large number of precipitates, such as Mg17Al12, Al8Mn5, Al11Mn4, Al11Ce3, Al3Ce, Al4Ce, Mg17Ce2, Al10Mn7Ce2, Mg2Ce, Mg3Ce, and Mg12Ce were observed in AME300 Mg alloy. They were found to be dissolved or disappeared with an increase in the temperature of annealing, which appeared to be increased the grain growth of AME300 Mg alloy at high annealing temperatures. It was further observed that abnormal growth of grains led to the weakening of basal texture in both pure Mg and AME300 Mg alloy. The ductility of the samples was found to be dependent on the reduction in basal texture intensity, whereas their tensile strengths were affected by the average grain sizes of the samples. AME300 Mg alloy had the best combination of tensile strength and ductility as compared pure Mg after annealing.