Enhancing the mechanical properties and wear resistance of plasma-sprayed Fe-based amorphous coatings by using graphite-partially-coated powders

For plasma-sprayed Fe-based amorphous coatings, the predominant factor contributing to their wear failure is the weak inter-splat bonding. Consequently, enhancing the intersplat bonding and reducing the friction are imperative to resolve this issue. In this study, graphite-partially-coated powders were utilized to prepare Fe-based amorphous coatings. The effects of graphite-partially-coated powders on the microstructure, mechanical properties, and wear resistance of the coatings were experimentally and numerically investigated. The experimental results demonstrate that the graphite-partially-coated powders enhance the amorphous content of the coating. The graphite within the coating shows an intermittent strip-shaped distribution at the inter-splat interfaces. With the increasing graphite coating ratio, there is a substantial enhancement in the mechanical properties of the coating. Concurrently, there is a notable reduction in the coefficient of friction and the wear rate. Additionally, the coating wear caused by delamination and oxidation is effectively mitigated. The simulation results demonstrate that the graphite significantly increases the temperature of Fe-based amorphous particles. The findings suggest that the utilization of graphite-partially-coated Fe-based amorphous powders can enhance the bonding quality between splats and reduce the friction, thereby enhancing the wear resistance of the coating.