Compaction of Ultra-Fine WC Powder by High-Speed Centrifugal Compaction Process

High-Speed Centrifugal Compaction Process (HCP) is one of slip-using compacting method originally developed for processing of oxide ceramics. In this study, we are going to apply the HCP to ultra-fine (0.1 micron) WC powder. Organic liquid of heptane was chosen as dispersing media to avoid possible oxidation of WC. For slip preparation, addition of sorbitan-monostearate (SMS) dramatically improved state of dispersion. The mixing apparatus also was in consideration. The slips mixed by conventional ball mill or turbula mill were scarcely densified by the HCP. Only the slips mixed by high energy planetary ball mill were packed up to 55% by the HCP, and sintered to almost full density at 1673 K without any sintering aids. This sintered compact marked Vickers hardness of Hv 2750 at maximum.