Influence of Technological Conditions on the Properties of PcBN Composites Fabricated by Spark Plasma Sintering

摘要

Polycrystalline cubic boron nitride (PcBN) composites were fabricated by spark plasma sintering (SPS). The SiC, Si_3N_4 and Si/B were used as binder. The effects of SPS sintering process parameters, such as the sintering temperature, holding time, heating rate and binder composition, on the properties of PcBN samples were investigated. PcBN composite with a hardness of 23.12GPa was fabricated efficiently by SPS. The hardness of PcBN sample increased first and then decreased with the increase of sintering temperature. As the holding time was 20 min, the hardness of PcBN sample was the highest. The PcBN performance at the heating rate of 50 °C/min was significantly better than that of 100°C /min. When the binder component of SiC, Si_3N_4, and Si was 63%:27%:10%, the hardness of PcBN was the highest. With an addition of Si, the PcBN samples had higher hardness than that of B.