Influence of Incorporating B4C Nanoparticles and Pulse Electrodeposition Parameters on the Surface Morphology and Wear Behavior of Nickel Based Nanocomposite Coatings

The main aim of this project is to fabricate a nickel-based nanocomposite coating reinforced with B4C nanocomposite coating by the means of pulse electrodeposition technique in nickel sulfate bath under high deposition rate and study the impact of pulse parameters on surface morphology and tribological properties. The coating surface morphology, chemical composition, microstructure, microhardness, surface topography, and ultimately wear behavior of coatings were assessed through scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Vickers hardness, atomic force microscopy, and pin-on-disk wear test, respectively. By the incorporation of B4C nanoparticles into the nickel matrix, the surface morphology was altered from pyramid to nodular structure. The maximum B4C incorporation was recorded to be 6.45 vol.% at 10 A/dm2, γ = 50%, and 10 Hz. The crystallite size of nickel crystallographic planes (111) and (200) reduced, so was the grain size. The microhardness of all composite samples was significantly enhanced. The weight loss and wear rate values of Ni-B4C composites were diminished and the minimum weight loss in the form of weight gain was dedicated to Ni-B4C sample fabricated at 10 A/dm2, by the -0.23 mg amount. The friction coefficient and average roughness were significantly increased. Notably, the wear morphology indicated the dominancy of adhesive wear specially in pure nickel sample, but it turned out to be abrasive wear for almost all Ni-B4C samples in which the its reduction was associated with the decrement of adhesion, plastic deformation, delamination, ploughing, and also a bit abrasive type of wear. Overall, the Ni-B4C sample fabricated at 10 A/dm2, γ = 50%, and 10 Hz, experienced the optimum wear resistance.