Microstructure and Diffusion Behaviors of the Diffusion Bonded Mg/Al Joint

Abstract

The diffusion and fracture behaviors of Mg/Al joints are investigated in this paper. The concentration distribution equations at each phase are calculated using Matlab, the predominant processing parameters that control the diffusion behaviors are discussed. The result indicates that the intermetallic compounds (IMCs) at the bonded interface of Mg/Al joint consist of Al3Mg2 layer (β) and Al12Mg17 layer (γ). Based on the Fick’s second law, the error function equations calculated by Matlab is in well accordance with the experiment of diffusion in Mg/Al diffusion bonding process. In addition, elements distribution and thickness of IMCs at the joint interface can be simulated by the error function equations. The microstructures of shear fracture surface show that cleavage steps occur at both fractures.

Keywords

• diffusion bonding
• intermetallic compounds
• diffusion behaviors
• fick’s second law
• brittle failure behavior