Microstructural and mechanical investigation of hot pressed WC-Co/B ₄C composites

Boron carbide addition into tungsten carbide-cobalt hard alloy in small quantities has been investigated to achieve a boron contained material. Tungsten carbide with content of 15 wt % Co, is used as the main component and boron carbide was admixed in quantities of 0.1 and 1.0 wt %. Powdery mixtures were then hot pressed at 1340°C under 50 MPa pressure effort and the final materials were characterized. SEM and EDS studies were made for microstructural phase characterization and particle size distribution analyses. Density, hardness and three point bending strength of the material were also determined, Beside WC and Co phases, formation of a third phase, composed of W, Co and B is observed in the final material. Addition of boron carbide to WC-Co alloy even in small quantities resulted an increase in hardness from 84 to 92 HRa.