Abstract
The present study investigates the influence of deformation mode on the microstructure evolution and plastic deformation behavior of AZ61 magnesium alloy. The material was processed using conventional extrusion and complex KoBo extrusion, resulting in different initial microstructures. Compression tests were performed at elevated temperatures and various strain rates to determine the flow stress behavior and plasticity characteristics of the alloy. The obtained stress-strain curves revealed significant differences in deformation behavior depending on the deformation mode and the initial microstructure. The material processed by the KoBo method exhibited lower flow stress and reduced peak stress compared to the alloy obtained by conventional extrusion. This behavior is associated with grain refinement and the enhanced activation of softening mechanisms during deformation. The results indicate that the refined microstructure accelerates the kinetics of dynamic recrystallization and improves the plastic deformation capability of AZ61 magnesium alloy.