A comparative study of effect of mechanical and ultrasound agitation on the properties of pulse electrodeposited Ni-W/MWCNTs composite coatings

The Ni-W/MWCNTs composite coatings with high MWCNTs content and evenly dispersed MWCNTs were successfully fabricated by pulse electrodeposition technique using ultrasound agitation. Effect of stirring method of plating solution on the morphology and microstructure of the Ni-W/MWCNTs composite coatings were evaluated. The surface of the Ni-W/MWCNTs composite coatings prepared using mechanical stirring is uneven and coarse and has poorly dispersed MWCNTs agglomerates, leading to low microhardness and inferior corrosion resistance and anti-wear of the composite coating. Different from mechanical agitation, ultrasound agitation uniformly distribute MWCNTs within the Ni-W/MWCNTs composite coatings, resulting in this coating displaying smoother surface, higher microhardness, better tribological and anti-corrosion properties. Besides, the morphology and properties of the Ni-W/MWCNTs composite coatings both be greatly influenced by the ultrasonic power. Particularly, the composite coating prepared with the ultrasonic power of 70W shows', due to the greatly incorporation and evenly distribution of MWCNTs in the composite coating. Generally, the differences of the wear and friction properties and corrosion resistance behaviors of the composite coatings prepared under different conditions are ascribed to the microstructures and microhardness.