Investigation on diffusion bonding of functionally graded WC–Co/Ni composite and stainless steel

A functionally graded WC–Co/Ni composite (FGWC) and 410 stainless steel (410ss) were successfully bonded by diffusion bonding. With the bonding temperature or holding time increasing, the tensile strength of the joints increased firstly and then decreased. The maximum tensile strength of the FGWC/410ss joints was 195 MPa bonded at 950 °C for 80 min. A diffusion layer was formed between the Ni layer and the 410ss as a result of the interdiffusion of Ni and Fe. The Ni layer could release the residual stresses of the FGWC/410ss joints. The fracture of the FGWC/410ss joints occurred in the Ni layer by the way of ductile fracture.