Influence of Electrodeposition Process Parameters and Si 3 N 4 Nanoparticle Concentration on Microhardness and Wettability of Ni-Co-Si 3 N 4 Nanocomposite Coatings

To improve the microhardness and wettability of steel C1045 substrates, Ni-Co-Si 3 N 4 nanocomposite coatings were fabricated successfully on steel C1045 substrates via electrodeposition with varying electrodeposition process parameters and Si 3 N 4 nanoparticle concentrations. The microhardness, surface roughness, and static contact angle of the coatings were analyzed using a microhardness tester, laser scanning confocal microscope (LSCM), and contact angle meter (OCA15E), respectively. The results showed that the plating solution temperature, current density, and Si 3 N 4 nanoparticle concentration played key roles in adjusting the microhardness and wettability of the samples. The variations in the process parameters and Si 3 N 4 nanoparticle concentration altered the contents of Co, Si, and N in the Ni-Co-Si 3 N 4 nanocomposite coatings. These alterations influenced the grain size and improved the microhardness of the samples. The microhardness of the coatings was 541.56 HV 0.05 when their grain size was 16.99 nm. Additionally, the variations in the process parameters and Si 3 N 4 nanoparticle concentration affected the surface morphology and altered the surface roughness of the coatings. These alterations influenced the wettability and improved the water contact angles of the samples. Furthermore, the water contact angle of the Ni-Co-Si 3 N 4 nanocomposite coatings was 143.1° when the surface roughness was 0.322 µm.