Silicon carbide bonded Diamond materials prepared by reactive infiltration with silicides

SiC-bonded diamond composite materials, which are produced by reactive infiltration of diamond preforms with liquid silicon, have excellent wear and thermal properties. During infiltration, SiC and residual silicon (2–10 vol.%) are formed. The residual silicon has a negative effect on the properties. To minimize this influence, the infiltration of the diamond preforms with eutectic mixtures of Si and TiSi2, and VSi2, as well as the infiltration of TiC-containing diamond preforms, was tested. The structures were analyzed in detail using scanning electron microscopy (including EDX and EBSD) and X-ray phase analysis. In the case of infiltration with TiSi2/Si and the TiC-containing preforms, the formation of TiC and the MAX phase (Ti3SiC2) was detected. The Si content in dense, completely infiltrated materials can thus be almost completely eliminated. This is mainly due to the changed passivation of the diamonds by the Ti-containing melts compared to the pure Si melt. The results show that SiC-bonded diamond composite materials with interesting mechanical and electrical properties can be produced in this way.