Effects of Energy Densities on Microstructure, Mechanical Properties, and Wear Behavior of Inconel 625 + Tungsten Carbide Coatings by Laser Cladding

The increasingly complex wear environment of petroleum drill collars has made existing equipment inadequate for current service requirements. In this study, Inconel 625/tungsten carbide (WC) composite coatings are prepared by laser cladding at different energy densities (energy density (ED), 22.22, 19.96, 18.18 J mm −2 ). The microstructure, mechanical properties, and wear resistance of coatings fabricated with different scanning speeds are systematically investigated using scanning electron microscopy, energy dispersive spectrometer, and electron backscatter diffraction, along with the underlying strengthening mechanisms. Experimental results shows that all samples exhibit good metallurgical bonding without defects such as pores or cracks. The phase composition of all samples consisted of γ‐Ni, WC, W 2 C, and Cr 7 C 3 . When the ED decreased to 19.96 J mm −2 , the sample achieved the highest hardness of 535 HV and the highest elastic modulus 219.5 GPa. Meanwhile, the sample demonstrated optimal wear resistance, which is positively correlated with hardness and consistent with Archard's law. The superior wear resistance resulted from the synergistic effects of grain refinement and dispersion strengthening. During dry reciprocating sliding friction, larger WC particles fractured while crack propagation bypassed smaller WC particles. Additionally, spherical WC exhibited higher effective resolved shear stress for crack propagation compared to other carbide morphologies, making it more resistant to crack initiation, propagation, and fracture.