Flow Behavior and Microstructural Evolution of ZW61 Alloy during Hot Compressive Deformation

摘要

The flow behavior and microstructural evolution of the ZW61 (Mg-6Zn-0.6Y-0.5Zr) alloy during uniaxial compressive deformation at temperatures of 250-400°C and strain rates of 0.5-0.001s~'.were investigated. The results indicated that the flow stress could be described with a power law equation related to the temperature and strain rate. Furthermore, the deformation microstructures at different strain rates and temperatures were different. Microstructural evolution deformed under 350 °C and 0.001s"1 found that the twinning and different modes of slip systems were selectively activated during deformation, and that misorientation in some grains increased with lattice rotation during hot deformation, which resulted in the gradual formation of new grain boundaries. In addition, dynamic recrystallization (DRX) preferably took place nearby the boundaries of original grains/twinning/slipping bands and coarse particles, which resulted in an inhomogeneous deformation microstructure, i.e. necklace microstructure.