Impact Wear of the Protective Cr₃C₂-Based HVOF-Sprayed Coatings

High velocity oxygen-fuel (HVOF) prepared CrC-based hardmetal coatings are generally known for their superior wear, corrosion, and oxidation resistance. These properties make this coating attractive for application in industry. However, under some loading conditions and in aggressive environments, the most commonly used NiCr matrix is not sufficient. The study is focused on the evaluation of dynamic impact wear of the HVOF-sprayed Cr₃C₂-25%NiCr and Cr₃C₂-50%NiCrMoNb coatings. Both coatings were tested by an impact tester with a wide range of impact loads. The Wohler-like dependence was determined for both coatings' materials. It was shown that, due to the different microstructure and higher amount of tough matrix, the impact lifetime of the Cr₃C₂-50%NiCrMoNb coating was higher than the lifetime of the Cr₃C₂-25%NiCr coating. Differences in the behavior of the coatings were the most pronounced at high impact loads.