High performance, light weight alloys are need-of-the particularly in the defense, automotive and aerospace sectors. Magnesium is a prime candidate since it is the lightest structural metal having a mass density of 1.74g/cm3 and is the sixth most abundant element in the Earth’s crust. But, as a metal with a Hexagonal close packed (HCP) crystal structure, it exhibits poor formability, yield asymmetry, edge cracking in rolling, and low ductility at room temperature. Activation of non-basal slip planes, suppression of twinning, and promotion of recrystallization mechanisms leading to texture randomization have been a few key strategies incorporated during alloy design to achieve better properties.
In this study, the effect of thermo-mechanical processing i.e., confined rolling on three Mg-Al alloys namely AZ31B, Mg-6%Al and Mg-9%Al was analyzed. Extensive microstructural analysis using advanced electron microscopy techniques revealed the occurrence of either partial (in case of Mg-9%Al) or complete dynamic recrystallization which in turn refined the grain size, improved both strength and ductility under compression and randomized texture. Correlation of rolling temperature, strain rate, %Al content with texture, twinning, recrystallization kinetics, deformation mechanisms, precipitation kinetics and morphology have shed light on creating the best processing route for each of these alloys to achieve optimal microstructure and improved compressive mechanical behavior.