Vacuum brazing titanium using thin nickel layer deposited by PVD technique

In this study, the evolution of the interfacial microstructure, hardness distribution, and the joint strength of vacuum brazed commercially pure titanium were evaluated. A thin nickel layer, with different thicknesses, was deposited by PVD technique to serve as the brazing filler metal. Test joints were processed at temperatures of 910 °C and 960 °C using a soaking time of 15 and 90 min. The experimental results showed that sound joints with a good wetting quality as well as lack of pores and cracks can be achieved at a brazing temperature of 960 °C. A Ti2Ni intermetallic compound was formed at the interfacial area at a soaking time of 15 min and with a deposition rate of 90 AH which was detrimental to the joint mechanical properties. Meanwhile, at a soaking time of 90 min, intermetallic compound was not detected and the diffusion of nickel was completed at all deposition rates which improve the shear strength of the joints.