Study of diffusion bonding of Ti-6Al-4V and ZQSn10-10 with metal interlayer

The diffusion bonding was carried out to join Ti alloy （Ti-6Al-4V） and tin-bronze （ ZQSn10-10 ） with Ni and Ni ＋ Cu interlayer. The microstructures of the diffusion bonded joints were analyzed by scanning electron microscope （SEM）, energy dispersive spectroscopy （ EDS ） and X-ray diffraction （ XRD ）. The results show that when the interlayer is Ni or Ni ＋ Cu transition metals both could effectively prevent the diffusion between Ti and Cu and avoid the formation of the Cu-Ti intermetallic compounds （Cu3Ti, CuTi etc. ）. But the Ni-Ti intermetallic compounds （NiTi, Ni3Ti） are formed on the Ti-6Al-4V/Ni interface. When the interlayer is Ni, the optimum bonding parameters are 830 ℃/10 MPa/30 min. And when the interlayer is Ni ＋ Cu, the optimum bonding parameters are 850 ℃/10 MPa/20 min. With the optimum bonding parameters, the tensile strength of the joints with Ni and Ni ＋ Cu interlayer both are 155.8 MPa, which is 65 percent of the strength of ZQSn10-10 base metal.