Review of Physical and Mechanical Properties, Morphology, and Phase Structure in Cr3C2-NiCr Composite Coatings Sprayed by HVOF Method

This review paper presents a detailed analysis of the influence of high-velocity oxygen–fuel (HVOF) spraying parameters on the microstructure formation and performance characteristics of Cr3C2-NiCr coatings. Key HVOF parameters, including the spray distance, oxygen-to-fuel ratio, powder feed rate, and spraying temperature, are examined in relation to their impact on coating properties. Structural parameters such as density, porosity, adhesive strength, and microhardness, which determine the mechanical behavior of the coating, are analyzed. Special attention is paid to wear resistance mechanisms, adhesion to the substrate, and resistance to fatigue failure. Additionally, the thermal stability of the coatings, their coefficient of thermal expansion, and oxidation resistance are investigated. This study also evaluates the morphology and phase composition of the coatings under different HVOF spraying conditions. An overview of modern diagnostic techniques, such as electron microscopy and spectroscopy, is provided. Compared to traditional surface treatment methods, HVOF spraying offers superior coating density, higher adhesion strength, and enhanced wear and corrosion resistance, making it an effective solution for extending the service life of components. Based on the findings, this paper highlights promising applications of Cr3C2-NiCr coatings in the aviation, power engineering, and mechanical engineering industries, where high wear resistance and thermal stability are crucial.