Hot Deformation Characterization of Homogenized Mg-Gd-Y-Zn-Zr Alloy During Isothermal Compression

The article investigates the hot deformation behavior of a homogenized Mg-13Gd-4Y-2Zn-0.6Zr (GWZK1342) alloy based on isothermal compression tests. The hot deformation characterization of the GWZK1342 alloy was investigated through the work-hardening rate θ and the inflection point of ln θ − ε curves; thus, the critical strain model was established. Furthermore, the hot deformation map was formulated based on the critical strain, steady strain and variation of power dissipation at different deformation parameters. The optimum parameters can be determined as the process parameters corresponding to the value of ln Z < 40, and the dynamic recrystallization (DRX) predominately operates to accommodate plastic deformation. The kink mechanism of the long period-stacking ordered (LPSO) phase predominately operates as ln Z exceeds 43. The broken lamellar 14H-LPSO phase can facilitate continuous DRX because of the reduced inhibition effect on lattice rotation and promote discontinuous DRX nucleation through a particle-stimulated nucleation (PSN) mechanism as ln Z is < 40.