Dissimilar Metal Joining of Ti and Ni Using Ti-Al Powder Interlayer Via Rapid Thermal Explosion Method

To achieve the low energy consumption and high strength joining between Ti and Ni, a novel joining method (rapid thermal explosion, TE) was developed for joining dissimilar metals using Ti-Al mixture powders as flux. The TE reaction temperature of Ti-Al flux was measured, and the microstructure and mechanical properties of Ti/Ni joint were investigated. The results reveal that the combustion temperature of the Ti-Al powder interlayer is 1103 °C, which is higher than the joining temperature, and an obvious self-exothermic phenomenon lasts 20 s. The intermetallic compound diffusion layers formed at both interfaces mainly owing to the diffusion of Al and the growth activation energy of diffusion layers near both interfaces are 79.68 kJ/mol and 38.26 kJ/mol, respectively. Based on the sheer strength and diffusion layer, the formation mechanism of Ti/Ni joints is metallurgical bonding through atomic diffusion and formation of the diffusion layer.