Influence of bonding temperature on solid-state diffusion bonded joints of AA2219 and Ti-6Al-4V dissimilar alloys—microstructure and mechanical characterisation

An attempt has been made to join aluminium alloy (AA) 2219 and titanium alloy Ti-6Al-4V by solid-state diffusion bonding (SSDB), as this process ensures no macroscopic deformation during the joining. The quality of SSDB joints formed at the bonding temperature in the range of 500–540 °C is evaluated using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The bonding strength of the joints is evaluated by shear test, and hardness is tested using the Vickers microhardness method. It is observed that the hardness and shear strength values are increased with an increase in bonding temperature owing to the formation of intermetallic compounds at the joint interface like Al₃Ti, Al₂Ti and AlTi. Maximum shear strength of 82 MPa and hardness of 286 HV_0.05 are observed for the specimen bonded at 540 °C.