Modification of texture and microstructure of magnesium alloy extrusions by particle-stimulated recrystallization

Abstract

Conventional magnesium alloy Mg–1Zn–0.4Zr and a modified version of the same alloy containing Nd-based rare earth mischmetal and Y were extruded at 400°C to study dynamic recrystallization and its role in the microstructure and texture development. Second phase particles in the modified alloy seemed to generate new orientations other than the deformed orientation. Although this occurred within small volume fraction of the material, the respective recrystallizing grains grew up to considerable sizes consuming larger volumes of the extruded microstructure and dominating the bulk texture. The consequent mechanical behavior tested in plane strain compression at room temperature demonstrated improved strain hardening behavior and enhanced ambient formability relative to the conventional alloy due to well-scattered texture and prolonged activity of basal slip within a large volume of the deformed microstructure.