Microstructure and XRD analysis in the interface zone of Mg/Al diffusion bonding

The microstructure and phase constituent for the Mg/Al diffusion bonded joint were studied via scanning electron microscope (SEM) and X-ray diffraction (XRD). The test results indicated that the new compact phase was formed near the transition region of Mg/Al diffusion interface. There are three new phase layers in the transition region. The fracture morphology mainly consists of coarse and gray fracture, and the fracture is mainly the mixed fracture of cleavage and brittleness. X-ray diffraction test indicates that the diffusion zone of Mg/Al diffusion bonded joint consists of intermetallic compounds MgAl, Mg3Al2 and Mg2Al3. With the increase of heating temperature, the content of Mg3Al2 and Mg2Al3 phases with good stability was improved.