Abstract
High velocity oxy-fuel spraying of WC-12Co was performed using a feedstock in which the WC phase was either principally in the micron size range (conventional) or was engineered to contain a significant fraction of nanosized grains (multimodal). Three different HVOF systems and a wide range of spray parameter settings were employed to study the effect on both the in-flight particle characteristics and coating properties. A process window with respect to particle temperature was identified for producing coatings with the highest resistance to dry abrasion. Although the presence of a nanosized WC phase produced harder coatings, there was little difference in the abrasion resistance of the best-performing conventional and multimodal coatings. However, there is a potential benefit in using the multimodal feedstock because of the possibility of higher deposition efficiencies and a more robust thermal spray process.
