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 TiSi 2 , and VSi 2 , 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 TiSi 2 /Si and the TiC-containing preforms, the formation of TiC and the MAX phase (Ti 3 SiC 2 ) 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.