Effect of Processing Route and Working Temperature on Microstructure Evolution of AZ31 Magnesium Alloy During Equal Channel Angular Pressing

AbstractMagnesium and its alloys are becoming promising materials for structural, aerospace, automobile and marine applications due to their light weight and high strength to weight ratio. Recently, magnesium alloys have found applications in biomedical engineering because of properties such as degradation in physiological environment and mechanical properties near to natural bone. Interest in developing magnesium based temporary implants has been growing for the past century. However, processing magnesium is difficult at room temperature due to insufficient number of slip systems. Magnesium needs to be heated to elevated temperatures to plastically deform. In the present work, AZ31 magnesium alloy was processed by equal channel angular pressing (ECAP) at 300°C in route C up to four passes. The role of working temperature and processing route on microstructure evolution was studied. Microstructural observations clearly showed fine grain structure achieved after ECAP. The role of grain size on hardness and wettability was investigated. The evolution of microstructure during ECAP and the recrystallization effect on grain growth during reheating of the samples for subsequent passes was investigated