A study of phase constitution near the interface of Mg/Al vacuum diffusion bonding

The characteristics of phase constitution near the interface of Mg/Al diffusion bonded joint are studied by means of scanning electron microscope (SEM), X-ray diffraction (XRD) and transmission electron microscope (TEM). The test results indicated that the obvious diffusion zone forms near the Mg/Al interface as a result of the vacuum diffusion bonding. The diffusion zone of Mg/Al diffusion bonded joint consists of intermetallic compounds MgAl, Mg3Al2 and Mg2Al3. The transition region on Mg side mainly consists of Mg crystals, and the new phase formed is Mg3Al2 intermetallic compounds. This is favorable to the enhancing of the combination strength for Mg substrate/diffusion zone.