Joining of Cf/SiC composite and 304 stainless steel assisted by surface honeycomb modification

Abstract A novel surface honeycomb modification was developed by pre-oxidizing the Cf/SiC composite, and the honeycomb modified Cf/SiC composite and stainless steel were brazed with AgCuTi filler. Results showed that a honeycomb-like surface with dense pores could be obtained when the Cf/SiC composite was air-oxidized at 700°C. During the brazing process, the liquid filler infiltrated into the pores and formed an infiltrated area, which not only significantly increased the bonding area between the reaction layer and the Cf/SiC composite, but also effectively hindered the crack propagation due to the nailing/pinning effect. The Finite Element simulation displayed that the infiltrated area transferred the stress concentration away from the reaction layer, dispersed the residual stress and reduced the corresponding stress value. As the result, the maximum shear strength of the joint reached 158MPa, which is multiple times higher than the joint without surface honeycomb modification.