Development of electro-co-deposited Ni–TiC nano-particle reinforced nanocomposite coatings

Abstract

In the present work, the Ni–TiC nanocomposites were electrodeposited from an organic free Watts' nickel electrolyte with suspended TiC nano-particles by direct current (DC) plating method. For this purpose, effects of average current density on the TiC phase precipitation, surface morphology, crystalline size and the amount of co-deposited TiC nano-particles were investigated. TiC nano-powders were co-deposited with nickel matrix on the brass substrates. The characterization of the coatings was performed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) facilities. The microhardness of resultant composite coatings was also measured and found to be 302 to 410HV, depending on the volume percentage of co-deposited TiC particles in the Ni matrix. The results also indicated that the optimum current density for obtaining the highest volume percentage of TiC particles and eventually, the maximum microhardness were 70mA/cm2. Optimizing of electro-co-deposition conditions lead to production of metal matrix composite coating with matrix crystalline size less than 40nm. The embedding TiC nano-particles in the metallic matrix resulted in the production of composite deposits with small crystallite size. Developed electro-co-deposited Ni–TiC nanocomposite coatings exhibited obviously (220) as the preferred orientation plane at low average current density and at its high value the coating preferred orientation was changed from (220) to (200) planes.