Effect of Zn interlayer thickness on the microstructure and mechanical properties of two-step diffusion bonded joint of ZK60Mg and 5083Al

Abstract Three different thicknesses of pure Zn interlayers were used in the two-step diffusion bonding between ZK60 magnesium (Mg) alloy and 5083 aluminum (Al) alloy. The effect of Zn interlayer thickness on the microstructure and the mechanical properties of the joints were investigated. The results showed that with the thickness of Zn interlayer increased, the width of the diffusion layers increased and the phase formed in the diffusion layer changed from Mg-Al-Zn ternary compounds to Mg-Zn binary compounds and Al-Zn solid solution. The microhardness of the Mg/Zn/Al joints was lower than that of the Mg/Al joint and the shear strength of the joint was improved by Zn interlayer addition. The maximum shear strength of 38.65 MPa was obtained from the Mg/Zn 50 /Al joint in which the laminar structure of MgZn 2 layer resisted the rapid propagation of cracks.