A review on Inconel 625 Alloy Metal Matrix Composite Coatings

Inconel 625 alloy exhibits excellent high-temperature performance and corrosion resistance, and is frequently employed as a protective coating material for oxidation resistance, corrosion resistance, and wear resistance. However, the relatively low hardness of Inconel 625 alloy limits its wear protection capability. To enhance the wear resistance, a certain amount of hard ceramic reinforcing particles is typically incorporated into the Inconel 625 alloy matrix to form metal matrix composite coatings. The current research status of Inconel 625 alloy composite coatings is reviewed in this paper. The characteristics of composite coatings deposited with different processes and with various reinforcing particles is summarized, the influencing factors and mechanisms of wear resistance enhancement in composite coatings are discussed, and the decomposition and agglomeration issues of reinforcement particles in coatings along with corresponding solutions are analyzed. The analysis indicates that laser cladding is the most commonly used process for Inconel 625 alloy composite coatings deposition. WC and TiC are the most frequently utilized reinforcing particles. The content of reinforcing particles is the most critical factor affecting the wear resistance of composite coatings. Process parameters, as well as the type, size, and shape of reinforcing particles, influence particle decomposition. The addition of carbon nanotubes can effectively restrict the agglomeration of reinforcing particles.