Dissimilar joining of TiAl alloy and Ni-based superalloy by laser welding technology using V/Cu composite interlayer

Joining TiAl alloy to Ni-based superalloy is of great interest for applications in aerospace and automobile field. In present study, we report the feasibility of TiAl alloy to Ni-based superalloy welding through V/Cu composite interlayer carried out by laser. Detailed microstructural characterization, mechanical properties and fractured behavior of the joints were performed. The V/Cu composite interlayer remarkably decreased the formation of brittle phases and eliminated subsequent cracking compared with no interlayer and eventually improvement of mechanical properties of the joints. The tensile strength of room temperature and high temperature (873 K) were 230 MPa (reaching about 60% of the TiAl base metal) and 145 MPa, respectively. The study results indicate that insertion of V/Cu composite interlayer is very useful for laser welding of TiAl/Ni-based superalloy.