9. Elements Diffusion in Brazing Seam of High Volume Fraction SiCp/6063Al Matrix Composites

In this research, 6063 aluminum matrix composites containing 55–75% SiC particle reinforcing phase was selected as the parent metal and Al-Cu24-Si5-Zn2-Ti1 alloy metal was selected as the filler metal. After nickel plating of the parent metal, the brazing process is carried out on vacuum brazing furnace under the temperature of 565, 570, and 575 °C and holding for 10, 20, and 30 min. The interfacial microstructure is investigated by light optical microscopy (LOM) and scanning electron microscopy (SEM), and the element diffusion is analyzed by energy spectrum analysis (EDS). The result shows that the nickel plating layer on the surface of parent metal not only metalizes the SiC particle, but also participates in the diffusion process. The element distribution in the brazing seam is described exactly. Finally, the reason why finest crystalline grains and evenest distribution could be achieved under brazing temperature of 575 °C and holding for 30 min is analyzed.