Resistance brazing of C/C composites-metallized SnAgCu-Ti powder to T2 copper using AgCuTi filler metal

Carbon/carbon (C/C) composites and T2 copper (Cu) alloy were successfully welded by the following two-step process: the pre-metallization on C/C composites was successfully prepared by the vacuum brazing welding using SnAgCu-xTi(x = 1, 2, 3, 4, and 5 wt%) metal powder and the subsequent reliable C/C composites-Cu joints were obtained by resistance brazing welding with AgCuTi filler metal as the interlayer in this paper. The typical interface morphology of the metallization layer on the surface of C/C composites, microstructure, mechanical properties, and fracture mechanism of resistance brazing welded joints were investigated by the relevant analysis method. The smooth metallization layer was generated on the surface of the C/C composites in the pre-metallization process successfully. The formed excellent bonding between the metallization layer and C/C composites in this stage was prepared for the subsequent welding process. Meanwhile, a strong interfacial bond was obtained due to the formation of the TiC reaction layer in the subsequent resistance brazing welding process. Molten solder infiltrated the pores of the C/C composites and formed a ‘pinning structure’. The residual thermal stress and mismatch of CTE could be relieved by the gradient layer and the shear strength could reach 19.68 MPa.