Microstructure, texture and mechanical properties of Mg-Gd-Y-Zr alloy annular forging processed by hot ring rolling

Abstract

Hot ring rolling (HRR) was successfully applied to fabricate large-size seamless magnesium alloy annular forging in this work and the resultant microstructures, texture and mechanical properties of the ring are discussed. Results show that the microstructures, along the thickness direction of the ring, are heterogeneously distributed, with the extent of dynamic recrystallization (DRX) differing among different sampling regions, owing to the inhomogeneous strain and temperature distribution. Typical basal texture is identified in all sampling regions, but with different degree of inclination or scattering of the {0002} basal poles. Due to the rotation of the basal poles towards some specific direction, the ring exhibits an obvious mechanical anisotropy. After aging treatment, the best comprehensive mechanical properties are obtained in the transverse direction of the outer region, with an ultimate tensile stress of 456MPa, yield stress of 426MPa and elongation to failure of 3.5%.