Sintering behavior and properties of diamond/cemented carbides

Dense diamond/cemented carbides were fabricated at around 1300 °C, 41 MPa for 3 min under meta-stable conditions for diamonds by pulsed-electric current sintering. Diamond particles were coated with SiC to prevent the graphitization of diamond with molten binder during sintering. No graphitization of diamond was confirmed by microstructure observation and Raman scattering analysis. The combination of SiC coating of diamond and rapid sintering was effective to fabricate diamond/cemented carbides. These new materials, composed of diamond and cemented carbide, showed a 50% larger fracture toughness and 10 times better wear resistance compared with conventional cemented carbides, and five times better machinability compared with diamond compacts. The diamond/cemented carbides are applicable to wear-resistant sliding tools such as centerless blades, work rests, and stoppers.