Corrosion, passivation and wear behaviors of electrodeposited Ni-Al2O3-SiC nano-composite coatings

The effect of the concentration of Al2O3-SiC nano-particles in an electrolyte bath on the structure, micro-hardness, wear resistance, corrosion performance, and passivation behavior of electro-co-deposited Ni-matrix composite coatings was investigated. Structure and texture studies were done by X-ray diffraction. The Vickers micro-hardness and wear resistance of the produced nano-composite coatings were evaluated and compared with the results of the pure Ni coating. The corrosion and passivation behaviors of the prepared coatings were investigated in an acidic 0.5 M Na2SO4 solution by a potentiostat-galvanostat device. It was found that by the nano-particle incorporation, the crystallographic texture of the Ni-matrix changes and the Ni crystallite size is considerably reduced to the nano-metric range. It was also realized that the micro-hardness, wear resistance, corrosion performance, and passivation behaviors of the coatings are significantly improved by the incorporation of the Al2O3 and SiC nano-particles into the Ni-matrix, provided that the optimum concentration of the nano-particles is utilized in the electrolyte bath.