Influence of NbC and TaNbC Additions on WC-Ni based Nanostructured Hardmetals

The need for Co replacement with alternative binders is imperative in hardmetals research due to environmental and health issues, high cost, and inferior corrosion properties. In combination with nano WC powders, alternative binders could reach the properties of WC-Co hardmetals with improved corrosion resistance. Nickel as a binder is one of the best cobalt alternatives due to its similar properties and enhanced electrochemical corrosion resistance. Previous studies indicated that adding niobium carbide to WC-Co hardmetals significantly refines grain size and limits grain growth. Depending on the amount of NbC in hardmetals, transverse rupture strength, hardness, and wear resistance can be improved. In contrast, TaNbC significantly improves oxidation, thermal and wear resistance, and hot-hardness. In this work, microstructural characteristics and mechanical properties were investigated by observing the influence of adding NbC and TaNbC to starting mixtures with a Ni content of 9 wt.% and a mean particle size of tungsten carbide of approximately 150 nm.