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

摘要

TiAl-based intermetallics joined by vacuum induction brazing using Ag-Cu35.2-Ti1.8 filler alloy at 850-970℃ for 1-10 min was investigated. The optimum brazing parameters are as follows: brazing temperature is 870-880℃, brazing time is 4—6 min. The maximum tensile strength of the joint is 320 MPa for the specimen induction brazed at for 870℃ 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℃ for 5 min is instable at 400℃. The instantaneous high temperature strength is 248 MPa at 400℃, 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.