Pulsed electrodeposition of Ni-B/TiN composites: effect of current density on the structure, mechanical, tribological, and corrosion properties

Abstract

Ni-B/TiN composite coatings with different current densities (1.5, 3.0, 4.5, and 6.0 A/dm(2)) have been successfully produced on a mild steel substrate using the pulsed electrodeposition (PED) method. The effect of current density on structure, morphology, hardness, tribological, and corrosion behaviors were investigated. It was found that the composite coating produced with a current density of 4.5 A/dm(2) exhibited, smooth surface a uniform fine compact and crack-free structure and the particles were distributed homogeneously in the metallic matrix. After the Ni-B/TiN composite coatings deposited on the substrate, samples were heat treated at 400 C for 1 h for providing precipitation of intermetallics to improve mechanical and tribological properties. In the electrochemical measurements performed in 3.5% NaCl solution by weight, the anti-corrosion ability of the composite coating was analyzed. According to the results obtained that current density is an important parameter affecting not only the deposition mechanism of Ni-B/TiN composite depositions but also microstructural, mechanical, tribological, and corrosion properties in the PED process. Accordingly, TiN particle reinforced Ni-B composite coatings deposited by the PED method are expected to be applied as a protective coating in industrial applications with excellent hardness, superior wear resistance and anticorrosion capability.