Study on microstructure, erosion resistance, wear resistance, and corrosion resistance of electrodeposited Ni–SiC coatings

Ni–SiC composite coatings containing SiC at concentrations of 0, 4, and 8 g/L were deposited on 45 steel substrates via electrodeposition to address the early degradation of 45 steel under the combined conditions of sand-containing erosion, sliding friction, and corrosion. Furthermore, the impact of introducing SiC on the microstructure, microhardness, critical load, corrosion, erosion, and wear resistance of the prepared coatings was systematically analyzed. The findings demonstrated that an optimal SiC particle content of 4 g/L effectively refined Ni grain structure, resulting in a dense, uniform coating, with reduced porosity. The coating displayed an increased microhardness value with increasing SiC addition, reaching 650.7 HV at 4 g/L, approximately 54.8% higher compared to the pure Ni coating. The critical load remained at a high level of 61.5 N, satisfying the requirements for industrial applications. The coating fabricated with 4 g/L SiC demonstrated optimal corrosion resistance, with a 59.4% reduction in self-corrosion current density and a 73.5% decrease in 336 h neutral salt spray weight loss compared with the pure Ni coating. The erosion volume loss at impact angles of 30° and 90° decreased by 66.0 and 65.4%, respectively, while the wear rate decreased by 61.4%. Excessive SiC particles (8 g/L) facilitate agglomeration, inducing increased internal defects and compromised critical load, corrosion, and erosion resistance. Therefore, the SiC addition of 4 g/L was identified as the optimum concentration under the present experimental conditions, in accordance with the comprehensive performance evaluation. This coating provides an optimal balance of hardness, toughness, critical load, and corrosion resistance, significantly enhancing the durability and extending the service life of 45 steel components under complex and severe service conditions.