Preparation of the Ni–P composite coating co-deposited by nano TiC particles and evaluation of it's corrosion property

Abstract

In current research, low carbon steel plates were coated by Ni–P electroless method. The effect of adding different concentrations (ranging from 0.01g/l to 0.5g/l) of TiC nano-sized particles to the plating bath on deposition rate, surface morphology and corrosion behavior of Ni–P–TiC composite coatings were investigated. The surface morphology and the relevant structure were evaluated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Corrosion behavior of the coated steel was evaluated by electrochemical impedance spectroscopy (EIS) and polarization techniques. The results showed that addition of TiC nano-particles to Ni–P electroless bath not only changes the surface morphology of Ni–P coating, but also improves corrosion resistance of the steel in comparison with TiC free Ni–P electroless coating. In addition, the deposition rate of coating was also affected by incorporation of TiC particles. It was also found that improvement in corrosion resistance largely depends on the phosphorous and TiC concentrations on the coatings.