Impulse pressuring diffusion bonding of titanium to 304 stainless steel using pure Ni interlayer

In the present study, impulse pressuring diffusion bonding technology (IPDB) was utilized between commercially pure titanium and 304 stainless steel (SS) using pure nickel (Ni) as interlayer metal. The interfacial microstructures of the bonded joints were investigated by scanning electron microscopy (SEM) and energy dispersive spectroscope (EDS) analyses. It is found that with the aid of the Ni interlayer, the interdiffusion and reaction between Ti and SS can be effectively restricted and robust joints can be obtained. Intermetallic compounds (IMCs) including Ti2Ni, TiNi, and TiNi3 are detected at the Ti/Ni interface; however, only Ni–Fe solid solution is found at the Ni/SS interface. The maximum tensile strength of 358 MPa is obtained by IPDB for 90 s and the fracture takes place along the Ti2Ni and TiNi phase upon tensile loading. The existence of cleavage pattern on the fracture surface indicates the brittle nature of the joints.