Electrodeposition and Characterization of Ni/Ti3Si(Al)C2 Composite Coatings

Pure nickel and Ni/Ti3Si(Al)C2 composite coatings were prepared by electrodeposition method from an additive-free nickel Watt's bath and were characterized by X-ray diffraction, laser confocal microscopy and scanning electron microscopy. The effect of current and Ti3Si(Al)C2 concentration in the solution on the composition, grain size, preferred orientation and surface morphology of the electrodeposited coatings were investigated. (200)-oriented Ni coatings could be deposited at high current (62.5 mA), while (220)-oriented Ni coatings could be obtained at low current (25 mA). However, the presence of Ti3Si(Al)C2 particles disturbed the surface texture of Ni crystallites in the composite coatings. Based on the simulated morphology and the observed microstructure, the mechanisms for the change of preferred orientation and crystallite shapes in the presence of Ti3Si(Al)C2 particles were discussed. Moreover, microhardness and friction properties of pure nickel and Ni/Ti3Si(Al)C2 composite coatings were also compared.