Preparation of Superfine-Cemented Carbide by Spark Plasma Sintering

摘要

92WC-8Co powder mixture with superfine-tungsten carbide was respectively sintered by spark plasma sintering(SPS)and sintering isostatic pressure (SIP). Complete dense samples with 200 nm WC grains and 94.2HRA hardness were prepared by spark plasma sintering at 1 150 ℃ and under 4.5 kN for 5 minutes. SIP was carried out at 1 400 ℃ for 30 minutes with a result of 300-400 nm WC grains and 93 HRA hardness. The results show that sintering temperature is greatly decreased by SPS, sintering time is largely shortened and WC grain growth is effectively retarded. Micropores and drawbacks in superfine-cemented carbide made by SPS are greatly declined, which is very useful to improving mechanical properties.