Joining of carbon/carbon composite with stainless steel using AgCuTi as brazing alloy and Nb interlayer

C/C composite and stainless steel were joined by using AgCuTi brazing alloy and Nb interlayer at the temperature of 900°C for 10 min. The microstructure and phase composition of the joint line were investigated by scanning electron microscopy (SEM) and x-ray diffractometer (XRD), respectively. Experiment results show that AgCuTi as brazing alloy and Nb as interlayer is a promising method for joining C/C composite and stainless steel; during joining process, a TiC reaction layer is formed at the interface of AgCuTi and C/C composite, which improves the joint strength between C/C composite and brazing alloy, some filling metal even infiltrates the C/C composite because of the existence of porosity in C/C composite, forming mechanical and metallurgical bond that improve the mechanical properties of the joint; the interface microstructure of C/C composite and stainless steel joints can be expressesd as C/C composite/TiC reaction layer/Ag(S. S)+Cu(S. S)/Nb/Ag(S. S)+Cu (S. S)+CuTi/stainless steel reaction layer containing Fe2Ti/stainless steel. The residual stress of the joint is greatly reduced by using Nb as interlayer and the maximum four-point bending strength of joints at room temperature is 72.20 MPa.