Cavitation erosion resistant nickel-based cermet coatings for monel K-500

WC-NiCr and WC-Hastelloy C coatings were deposited on Monel K-500 substrate by HVOF-spray with an aim to enhance cavitation erosion resistance of the alloy. The cavitation tests were performed for 10 h following ASTM G32-10 standard. Both WC-NiCr as well as WC-Hastelloy C coatings successfully reduced the erosion volume loss of the alloy by 59% and 9% respectively. The relatively superior performance of WC-NiCr coating could be attributed to better combination of its microhardness and fracture toughness. Formation of craters, cavities, and debonding of splats were found to be the signatures of cavitation erosion in the coatings. Whereas, microplastic tearing and microcracks were observed as the primary erosion mechanism in Monel K-500.

Automated summary

WC-NiCr and WC-Hastelloy C coatings were deposited on Monel K-500 substrate using HVOF-spray to enhance the cavitation erosion resistance of the alloy. Both coatings reduced the erosion volume loss of the alloy, with WC-NiCr showing a superior performance due to its better combination of microhardness and fracture toughness. The cavitation erosion in the coatings was characterized by the formation of craters, cavities, and debonding of splats, while microplastic tearing and microcracks were observed as the primary erosion mechanism in Monel K-500.