Abnormal twinning behaviors in ZK60 alloy by powder metallurgy process

A novel Mg-5.1 wt%Zn-0.18 wt%Zr (denoted as ZK60) alloy with a bimodal-grained structure (BGS) was fabricated via powder metallurgy (PM), which exhibits higher strength, ductility and tension/compression symmetry than fine grains prepared by other progress. Through detailed electron backscatter diffraction (EBSD) analysis, fine grains (DRXed) with weaker basal texture (0001) <11–20> are favorable for basal slip and early deformation. When the fine grains are filled with dislocations, the coarse grains (unDRXed) could accommodate abundant newly formed dislocations and the strong (11–22) <11–23> pyramidal texture promote the pyramidal slip, thereby suppressing {10–12} extension twinning (ET).