Modeling of process parameters and wear performance investigation of Inconel 625 nickel-based coatings via laser cladding

Abstract

In this study, laser cladding technology was employed to fabricate Inconel 625 coatings on the surface of 15CrMo alloy steel. The formation appearance, melt width, dilution rate, composition, microstructure, microhardness, and wear behavior of the coatings were investigated using X-ray diffraction (XRD), optical microscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), microhardness testing, wear testing machines, and laser confocal microscopy. Experimental results indicate that an optimal linear energy range of 10.8–14.4 W·min/mm and a powder feeding density range of 0.125–0.16 g/mm yield high-quality coatings with well-formed structures, refined grains, and enhanced microhardness. For the first time, the concept of powder feeding density was introduced. Based on the functional relationships between linear energy, powder feeding density, and coating characteristics, bead width and dilution rate models for Inconel 625 coatings were established, providing a theoretical basis for engineers to optimize the laser cladding process. Furthermore, friction and wear test results demonstrated that the coatings possess excellent wear resistance under optimal parameters, with the primary wear mechanisms being adhesive wear and oxidative wear.