Decarburization and improvement of ultra fine straight WC–8Co sintered via microwave sintering

Cemented tungsten carbide with ultra fine grains was prepared via microwave sintering. η phase (W3Co3C) was formed on the surface of the samples during the preparation process. Extra carbon black was premixed and the influence of carbon content on mechanical properties was studied. The results show that the maximum value of hardness and transverse rupture strength are HRA 93.2 and 3396 MPa respectively when the carbon black content is 0.45%. The microstructure investigated by SEM show that the WC grains growth mainly occurs during the early stage of microwave sintering by the coalescence of grains.