Interface structure and mechanical properties of the TiAl/42CrMo steel joint vacuum brazed with Ag–Cu/Ti/Ag–Cu filler metal

TiAl and 42CrMo steel were vacuum brazed with Ag–Cu/Ti/Ag–Cu filler metal. The joint interface was divided into three distinct zones, including the reaction layer near TiAl, the central zone, and the TiC reaction layer adjacent to the steel. During brazing, AlCu2Ti, AlCuTi and TiC phase formed quickly with an increase in brazing temperature or brazing time. By comparing the brazing conditions and joint strengths, the optimum brazing parameters were obtained. When brazed at 900 °C for 5 min, the room temperature tensile strength and shear strength of the joint were 347 MPa and 229 MPa, respectively.