Hot‐Compression Behavior of Two ZK60 Magnesium Alloys with Micron and Submicron Grains

This study mainly investigates the hot compression behavior and dynamic recrystallization (DRX) mechanisms of fine‐grained (FG) and coarse‐grained (CG) ZK60 magnesium alloys, revealing significant differences in their deformation characteristics and microstructural evolution. Under hot compression, FG ZK60 demonstrates a higher peak stress (206 MPa), lower critical DRX strain (0.004), and lower peak strain (0.18), whereas CG ZK60 exhibits a lower peak stress (185 MPa) but higher critical DRX strain (0.02) and peak strain (0.25). The deformation mechanism in FG ZK60 is dominated by basal and non‐basal slip systems, along with multi‐system slip, while twinning activity is notably suppressed. In contrast, CG ZK60 undergoes basal slip accompanied by tension twin formation. Regarding the DRX mechanisms, CG ZK60 exhibits a combination of twin‐induced DRX (TDRX), continuous DRX (CDRX), and discontinuous DRX (DDRX), while FG ZK60 predominantly relies on CDRX and DDRX. Furthermore, FG ZK60 exhibits weaker texture compared to CG ZK60, attributed to the competition between texture weakening by DRX grains and texture strengthening from sub‐grains or deformed grains. The study provides valuable insights for optimizing the high‐efficiency thermomechanical processing of magnesium alloys.