Induction brazing TiAl/40Cr with Ag-Cu-Ti filler metal

Induction brazing of TiAl to 40Cr under the protection of Ar gas was carried out with Ag-Cu-Ti filler metal. Fracture surface, inter facial microstructures and formation phases of brazed joints were investiga ted by means of scanning electron microscopy, electron probe microanaly sis and X-ray diffraction, and the joint strength was determined by tensile testing method. The results show that Ti(CuAl)₂,Ags,s,TiC form in the brazing seam and the typical interface structure of brazed joints is TiAl/Ti (CuAl)₂+Ag s, s/Ag s, s/TiC/40Cr. The tensile strength and fracture path of the brazed joints change with brazing time. When the joint is brazed at 1 143 K for 0.9 ks, joint tensile strength as high as 298 MPa is obtained and the fracture occurs in the Ti(CuAl)₂ zone.