Toughening of a vacuum diffusion-bonded heterostructured AZ31/WE94/AZ31 alloy by interfacial reinforcement

Abstract

Heterostructured materials have recently attracted extensive attentions from the materials community due to their superior combination of strength and ductility as compared to the conventional homogeneous counterparts. In the present study, the laminate AZ31/WE94/AZ31 Mg alloy was produced by vacuum diffusion bonding. The post annealing was carried out to improve the mechanical properties of the heterostructured Mg alloy. It is found the elemental diffusion and formation of interfacial phases enhance the interface bonding strength, thereby improving the comprehensive mechanical properties. The laminate sample annealed at 470 °C for 12 h shows a superior mechanical properties with a yield strength, ultimate tensile strength, and elongation of 158 MPa, 212 MPa and 12.9%, respectively. The higher annealing temperature leads to the growth of interfacial phase, which provides preferential nucleation sites for crack initiation and weakens the tensile properties.