Effect of Rolling Deformation on Microstructure and Mechanical Properties of As-Cast and Rolled ZM21 Magnesium Alloy

The current study aimed to improve the microstructure and mechanical properties of ZM21 magnesium alloy by using the rolling thermomechanical process at various temperatures (275 and 375 °C) and rates (40 and 60%). The rolled samples' grain size was examined, and it was found that the grain size decreased by 40% during hot deformation, reaching a grain size of 15.91 μm. Surface roughness values were examined and found to be the lowest (parallel and perpendicular to the rolling direction) at a 60% rolling rate in 275 °C and the highest 40% at 375 °C. The highest tensile strength was obtained at a rolling rate of 60% at 375 °C, but it showed brittle fracture during testing. Accordingly, while the 275 °C rolled samples showed ductile fracture behavior, a slight reduction in mechanical properties was observed when the rolling ratio was set at 60%.