Hot compression behavior and 3D processing maps of Mg-Gd-Y-Zn alloy formed by cold metal transfer wire arc additive manufacturing.

This article focuses on the hot deformation behavior and workability of a Mg-Gd-Y-Zn-Zr alloy (designated GWZ932) fabricated by cold metal transfer wire arc additive manufacturing (WAAM-CMT). Hot compression tests conducted between 350 and 500 °C and strain rates from 0.001 to 1 s⁻¹ revealed that peak stress decreases with increasing temperature and decreasing strain rate, with an average dynamic recrystallization activation energy (Q) of 308.4 kJ/mol. A constitutive equation describing the alloy's flow stress during hot deformation was established, and three-dimensional (3D) processing maps identified instability domains at 350–385 °C (0.1–1.0 s⁻¹) and 435–500 °C (0.4–1.0 s⁻¹), while the optimal workability domain was found at 435–500 °C with strain rates of 0.001–0.04 s⁻¹. Dynamic recrystallization during deformation significantly refines the grain size, reducing it by up to 74.6%, which informs the selection of processing parameters for integrating additive manufacturing with micro-forging of magnesium rare earth alloys.