Influence of Electrodeposition Process Parameters and Si3N4 Nanoparticle Concentration on Microhardness and Wettability of Ni-Co-Si3N4 Nanocomposite Coatings

To improve the microhardness and wettability of steel C1045 substrates, Ni-Co-Si3N4 nanocomposite coatings were fabricated successfully on steel C1045 substrates via electrodeposition with varying electrodeposition process parameters and Si3N4 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 Si3N4 nanoparticle concentration played key roles in adjusting the microhardness and wettability of the samples. The variations in the process parameters and Si3N4 nanoparticle concentration altered the contents of Co, Si, and N in the Ni-Co-Si3N4 nanocomposite coatings. These alterations influenced the grain size and improved the microhardness of the samples. The microhardness of the coatings was 541.56 HV0.05 when their grain size was 16.99 nm. Additionally, the variations in the process parameters and Si3N4 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-Si3N4 nanocomposite coatings was 143.1 degrees when the surface roughness was 0.322 mu m.