Effects of microwave sintering temperature and soaking time on microstructure of WC-8Co
(1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. School of Materials Science and Engineering, Kunming University of Science and Technology,
)
2. School of Materials Science and Engineering, Kunming University of Science and Technology,
)
Abstract: WC-8Co cemented carbide samples were processed via microwave irradiation in a 2.45 GHz, high-power multi-mode microwave cavity. The densification of the compacts and the microstructures of the prepared alloys were studied. The results demonstrate that the liquid phase is formed around 1300 °C and nearly full densification is obtained at 1450 °C for 5 min via microwave irradiation. The microstructures of microwave sintered samples have finer and more uniform WC grains than those of vacuum sintered samples. Besides, the WC grain size and distribution are only decided by the sintering temperature. Holding time has negligible effects on them. No matter how holding time is, the mean grain size is 2.7 μm when the sintering temperature is kept at 1450 °C.
Key words: tungsten carbide; microwave sintering; cobalt binder; microstructure; grain size