Joining of Cf/SiC composite with a Cu–Au–Pd–V brazing filler and interfacial reactions

A new Cu–Au–Pd–V filler alloy was designed for the joining of Cf/SiC composite. Its wettability on the composite was studied with the sessile drop method. After heating at 1473 K for 10 min the filler alloy showed a low contact angle of 5°. The interfacial reactions under the brazing condition of 1443 K/10 min resulted in the formation of VC0.75 reaction band at the surface of the composite, and the microstructure in the central part of the joint is composed of Cu(Au, Pd) solid solution and Pd2Si compound. The average three-point bend strength of the Cf/SiC–Cf/SiC joints at room temperature is 135 MPa. The joints also exhibit stable strengths at high temperatures of 873–1073 K. The presence of refractory Pd2Si compound within the Cu(Au, Pd) solid solution matrix throughout the joint should contribute to the stable high-temperature property.