Preparation of nanocrystalline WC-10Co-0.8VC by spark plasma sintering

摘要

WC-Co cemented carbides are widely used for cutting tools and wear resistant components. For more than 70 years, much effort has been spent trying to develop a material with an optimum combination of apparently opposing properties, hardness and toughness. Reduction of the WC size to the nanoscale is considered to be an effective method. However, nanograin WC tends to coarsen during sintering due to the high interface area between WC particles and the cobalt phase [1]. Therefore, grain growth inhibitors, such as VC and Cr_3C_2, are commonly added in order to retarded the growth process. It seems, however, that it is better to minimize the sintering time, since an additional 30 s results in an increase in WC grain size from 0.2 um to 2 um when WC-10Co is heated at 1400 ℃ [1].