The effect of deformation processing on the microstructure and mechanical properties of Mg-Y-Gd-Zr alloy

Abstract

Microstructure and properties of the magnesium alloy Mg-3.5Y-5.5Gd-0.3Zr (wt. %) have beenstudied after hot extrusion and rotary swaging. The effect of the deformation method on thekinetics of the decomposition of the magnesium supersaturated solid solution at 200 °C has beeninvestigated. The mechanical properties of the alloy at room temperature have been determined bothafter deformation and after additional strengthening aging. It has been shown that deformation leadsto grain refinement of the cast structure from ~50 μm to ~9 μm after hot extrusion and to ~16 μmafter rotary swaging, respectively. After deformation, the alloy can be additionally strengthenedby the aging treatment, with hot extrusion and, to a greater extent, rotary swaging accelerating thedecomposition of the supersaturated magnesium solid solution. Hot extrusion enhances both strengthand plastic properties, while rotary swaging provides the highest achievement of strength propertieswith a decrease in ductility. After rotary swaging and aging, the alloy exhibited an ultimate tensilestrength of ~485 MPa, yield strength of ~460 MPa, and elongation of ~4.5%.