LAUSR

Cu-55 vol.%diamond-1 vol.%Ti composites were fabricated by hot-forging of powder mixtures (referred to as M-Cu/Dia) and cold-pressed powder preforms (referred to as P-Cu/Dia). Dispersion of diamond particles in the size range of 70–80 µm at 55% volume fraction was attained in the P-Cu/Dia composites while diamond agglomerations were observed in the M-Cu/Dia composites. TiC was observed at the copper/diamond interface in both composites, in which most diamond particle surfaces (> 95%) were enveloped by TiC. It was found that TiC formed preferentially on the diamond-{100} facets compared with the diamond-{111} facets, which can be attributed to the fact that the C atoms are bonded by two C–C bonds on the diamond-{100} facets (more active) while three C–C bonds on the diamond-{111} facets (less active). The dispersion of diamond particles and formation of a TiC interface layer contributed to the thermal conductivity (388 W/mK) of the P-Cu/Dia composites, which is nearly twice that of pure copper hot-pressed from powder.