High-pressure synthesis and performance analysis of WC-cBN-MoS₂ self-lubricating ceramic composites

WC-cBN-MoS₂ self-lubricating ceramics were synthesized by using high pressure and high temperature sintering method. An analytical model of the self-lubricating properties has been developed to reveal the interrelationship between mechanical and self-lubricating properties. The influence of mechanical and self-lubricating properties of ceramics on the wear rate were analyzed. Self-lubricating performance optimization criterion are proposed accordingly. It was found that MoC, WS₂ can be formed during sintering, which can ensure self-lubricating and low temperature sintering properties. Adhesive wear is the main wear mechanism, the extent of which varies with the content of self-lubricating components. The high modulus of elasticity is the main reason for the excellent self-lubricating and mechanical properties of composites. The well-sintered WC-cBN-MoS₂ bulks present an excellent self-lubricating property with a hardness of 26.3 GPa and fracture toughness of 10.5 MPa·m^1/2, which is improved at least by 52% and 46% respectively compared with the traditional self-lubricating ceramics.