Nanocomposite Co-nSiC coatings electrodeposited from cobalt-gluconate bath via pulse reverse plating technique with anionic surfactant

Abstract

The co-deposition of silicon carbide nanoparticles (50 ± 5 nm diameter) in an electrodeposited metallic cobalt matrix has been investigated under pulse reverse plating (PRP) conditions with the inclusion of an anionic surfactant. The effect of variable anionic surfactant content in the plating solution with a particle content of 5 g L−1 was evaluated using both direct current (DC) plating and PRP. The particle content of the coatings was investigated by varying the cathodic cycle during PRP by varying the cathodic cycle time between 30 and 240 s per pulse whilst maintaining a fixed anodic charge. The coatings were assessed by SEM and EDX in cross section to determine the effect of PRP parameters and anionic surfactant content on the particle content of. With no anionic surfactant, all coatings produced contained a similar particle content. Addition of anionic surfactant affected the SiC content of DC and PRP coatings. PRP combined with anionic surfactant to produce an electrophoretic nanoparticle delivery mechanism increasing the SiC content of coatings compared to DC coatings. Higher SiC content was observed at shorter cathodic cycle times.