Microstructure and strength of the TiAl/40Cr joint diffusion-bonded with Ti-V-Cu filler metal

In this study, intermetallic TiAl and steel 40Cr are diffusion bonded successfully by using a composite barrien layer Ti/V/Cu. In this case, a diphase Ti 3Al+TiAl layer and a Ti solid solution which enhance the strength of the joint are obtained at the TiAl/Ti interface. The interface of TiAl/Ti/V/Cu/40Cr was free from intermetallic compounds and other brittle phases, and the strength of the joint was as high as 420 MPa , very close to that of the TiAl base. This method gives a reliable bonding of intermetallic TiAl and steel 40Cr.