Effect of CeO2 Addition on the Microstructure and Properties of Induction Heating Ni-WC-CeO2 Composite Coatings

Abstract

In this study, a BTG–15kW high-frequency induction heater was utilized to fabricate composite coatings of Ni-WC-CeO₂ with varying CeO₂ content on the surface of ASTM A36 steel substrates via induction cladding. The effects of CeO₂ content on the phase composition, microstructure, elemental distribution, cross-sectional microhardness, surface hardness, Rockwell hardness, wear resistance, and wear scar morphology of the composite coatings were systematically examined using XRD, SEM, EDS, microhardness testers, Rockwell hardness testers, friction and wear testing machines, OM, and stylus profilers. The aim was to identify the optimal CeO₂ content for enhancing coating performance. The results indicated that the incorporation of CeO₂ promotes elemental inter-diffusion both within the coating and between the coating and the substrate, facilitates the dispersion of WC, and enhances the cross-sectional microhardness and wear resistance of the coating. However, excessive CeO₂ content did not lead to further improvement, suggesting the presence of an optimal concentration. Among the compositions studied, the coating with 0.5% CeO₂ exhibited minimal internal defects, pronounced elemental inter-diffusion, uniform WC, the highest cross-sectional microhardness and surface hardness, and the second-highest wear resistance, identifying this composition as the most effective for achieving superior coating performance.