Strong and ductile texture-free ultrafine-grained magnesium alloy via three-axial forging

Abstract

We describe here the ingenious concept of combining annealing of as-cast alloy with multi-axial forging (MAF) (forging along x, y, and z-directions) that was applied to thermo-mechanically process a lean magnesium-rare earth alloy and obtain high strength and high ductility combination. This approach interestingly led to texture-free ultrafine-grained (UFG) structure with high yield strength of ∼227 MPa and elongation of ∼30 %. The objective of the study is to describe the preliminary findings and elucidate the evolution of texture in the MAF alloy in conjunction with the microstructure and mechanical properties. The discovery of the contribution of MAF in influencing texture, microstructure and mechanical properties is important from the perspective of current challenge in the processing of Mg alloys that has a hexagonal close-packed (HCP) lattice with limited slip systems, which makes it difficult to thermo-mechanically process at low temperatures.