Interfacial structure evolution of Ti-coated diamond particle reinforced Al matrix composite produced by gas pressure infiltration

Abstract The interfacial structure evolution of Ti-coated diamond particle reinforced Al matrix composite produced by gas pressure infiltration has been studied systematically, aimed to provide an insight into the optimization of interfacial structure and properties of the composite. The results show that the Ti coating layer on diamond particle consists of three layers, including fine TiC grains, TiC columnar grains and dispersed Ti particles. During the infiltration of molten Al, the dispersed Ti particles react with Al to form Al 3 Ti particles in Al matrix, while both TiC layers remain unchanged. However, in the subsequent cooling process, Al 4 C 3 particles are formed along the grain boundaries of TiC columnar grains as a result of Al diffusion and the subsequent Al/TiC reaction. By controlling the thickness of the TiC layers on diamond surface, an optimized thermal conductivity of 650 W m −1  K −1 is obtained for the composite. The finding is beneficial to the understanding of diamond coating engineering in the diamond particle reinforced Al matrix composite.