Mechanical property of induction brazing TiAl-based intermetallics to steel 35CrMo using AgCuTi filler metal

TiAl-based intermetallics joined by vacuum induction brazing using Ag–Cu35.2–Ti1.8 filler alloy at 850–970 °C for 1–10 min was investigated. The optimum brazing parameters are as follows: brazing temperature is 870–880 °C, brazing time is 4–6 min. The maximum tensile strength of the joint is 320 MPa for the specimen induction brazed at for 870 °C for 5 min, and at this time, the thickness of Al–Cu–Ti intermetallic compound layer is about one third of that of the whole interface. Interfacial microstructure of TiAl/Ag–Cu–Ti/35CrMo joint brazed at 870 °C for 5 min is instable at 400 °C. The instantaneous high temperature strength is 248 MPa at 400 °C, the fracture location of joint is mainly at Al–Cu–Ti intermetallic compound layer, the fracture pattern of brazed joint deviate from transcrystalline crack at room temperature into intergranular crack.