Microstructure in interface zone of diffusion-bonded joint of Mg/Al dissimilar materials

Magnesium (Mg1) and aluminum (1070 A) were bonded by vacuum diffusion bonding technology. The microstrueture of the Mg/Al diffusion bonded joint was studied by means of metallography, micro-hardness test, scanning electron microscope and X-ray diffraction. The diffusion bonding parameters: the heat temperature T_p=450-490℃,the pressure P=0.08-0.10 MPa, the holding time t=40-60 min.The experiment results indicated that the new compact phase was formed in the transition zone of Mg/Al diffusion bonded joint. The fracture morphology of Mg/Al diffusion bonded joint mainly consists of coarse and gray fracture, and the fracture is mainly the mixed fracture of cleavage.There are the intermetallic compounds MgAl, Mg₃Al₂ and Mg₂Al₃ in the diffusion transition zone.