A comparative study of the effect of mechanical and ultrasound agitation on the properties of electrodeposited Ni/Al _2O _3 nanocomposite coatings

摘要

In our study, Ni/Al _2O _3 nanocomposite coatings were obtained by electrochemical deposition of alumina nanoparticles from nickel Watts baths with different concentrations of Al _2O _3 particles in solution. A comparison of the effects of mechanical (300rpm) and ultrasonic (24kHz, 38Wcm ~(-2)) stirring on the properties of electrodeposited Ni/Al _2O _3 composite coatings was performed, observing an enhancement of the Al _2O _3 incorporation in the composite coating and an improvement of the uniformity of particles distribution in the nickel metal matrix when ultrasonic energy was applied to the process. Moreover, the characterization of the coatings also showed that for both types of agitation, the incorporation of Al _2O _3 nanoparticles led to changes in the morphology and structure of the nickel matrix leading to an improvement of its tribological properties. These properties were further enhanced when ultrasonic stirring was used during the composite coating electrodeposition.