The effect of Ti/Si ratio for introducing diamond into Cu melts based on Ti-Si-diamond reaction

In this study, diamond-reinforced Cu matrix composites were successfully prepared by introducing diamond into Cu melts based on Ti-diamond (D)-Si reaction. When TiD mixture is added into Cu melts, TiC will be immediately synthesized on the surface of the diamonds and tend to connect with each other to form a network structure, which will lead to the formation of the Cu-Ti-D refractory block. When Si is added into TiD, TiSi reaction will precede TiD reaction and form Ti5Si3. In this case, the formed TiC will be prevented from forming a continuous network. As a result, the diamond with the TiC shell will be effectively dispersed into Cu melts. It is found that the effect of Ti and Si on the microstructures of the prepared Cu-Ti-Si-D composites is not independent but related to each other, and the optimal mass ratio of Ti-Si-D is in the range of 2:(0.83–1.11):(1–1.25).