Fracture Mode and Joint Strength for Brazing of SiCp/LY12 Metal Matrix Composite with Al-Cu-Si-Mg Filler

Abstract:

The brazing of SiC particulate reinforced LY12 alloy matrix composite has been carried out by using the high-frequency induction vacuum brazing process with Al-28Cu-5Si-2Mg filler.The results showed that brazing temperature, holding time, SiC particle volume percentage and post heat treatment condition combine to influence the joint strength of SiCp/LY12. The SiC particles occur in the brazing seam and the distribution of SiC particles in the joint is not as uniform as that in the composites. Particle-poor zones in the joint exist near the base metal, and particle-rich zones exist in the center of the brazing seam. In addition, the results indicate that the failure of the composite is predominantly initiated by microcracks initiating at the SiC particle in the brazing seam and propagated along it with low energy.