2003 Volume 44 Issue 11 Pages 2339-2345
WC-10Co-xVC alloys were produced using two different sizes of WC powders (200 nm and 4.4 μm) via planetary milling and a liquid-phase sintering technique. When VC was added to the WC-Co alloys, the growth of WC particles was effectively suppressed. However, this process was dependent on the amount of additive used. Since the average WC particle size became less than 1 μm, the system experienced a significant loss in carbon, resulting in the formation of an undesirable η phase. The goal of this study was to determine the role of VC in controlling growth and to verify its effectiveness as a function of average WC size and inhibitor content. It was found from XRD and HREM studies that the (W,M)C phase was formed in WC-10Co-xVC-C systems. The effect of V or VC on the solubility of W in the Co matrix was also examined using HREM/EDS. The findings indicate that the presence of VC tends to reduce the solubility of W in a Co melt, thus inhibiting the dissolution and growth of WC.
