WC-Co-Re cemented carbides: Structure, properties and potential applications

Cemented carbides of the WC-Co-Re system represent a new class of hard materials having a significantly increased Young's modulus, hot hardness and high temperature creep resistance. The WC-Co-Re phase diagram was evaluated and compared with the corresponding WC-Co phase diagram. Physical and mechanical properties of such composites were measured at room and elevated temperatures and compared with those of conventional WC-Co cemented carbides. Microstructures of the WC-Co-Re cemented carbides at different carbon contents, binder contents and WC grain sizes were examined. Rhenium being dissolved in the Co-based binder is found to be a very strong grain growth inhibitor with respect to WC coarsening during liquid-phase sintering. The Young's modulus, hot hardness and high temperature creep resistance of the WC-Co-Re cemented carbides are greater than those of conventional WC-Co cemented carbides. Due to their unique properties the WC-Co-Re materials can find applications in use in high-pressure high-temperature components for synthesis of diamond and c-BN and cutting Ni-based super alloys and other heat-generating workpiece materials.