Cu-TiCx-bonded diamond composites were prepared by insitu reaction sintering of Cu, Ti3AlC2, and diamond powders. The effect of Ti3AlC2 content on the phase composition, microstructure, and grinding properties was investigated. Ti3AlC2 was decomposed to TiCx and Al. Then, Al was dissolved into the crystal lattice of Cu to form a Cu(Al) solution. A carbon-rich transition layer was formed at the ... [Show full abstract] interface between the diamond and the matrix. Excess Al inhibited the formation of Cu solid solution and reacted with Cu to form Cu3Al2. Diamond may be damaged to some extent by adding excess Ti3AlC2 in the raw materials, which may deteriorate the grinding performance of the composites. The grinding ratio value of copper-diamond composite was only 132, whereas that of the composites containing higher Ti3AlC2 content in the raw materials was approximately 350.