Wear and corrosion resistant properties of electrodeposited Ni composite coating containing Al2O3–TiO2 composite powder

Abstract

Electrodeposited Ni composite coatings containing ceramic particles have been widely investigated due to their improved mechanical, wear and corrosion resistant properties over plain nickel coatings. The application of one of the most widely studied plasma spray powder, Al2O3–13 wt-%TiO2, has not been explored in electrodeposited nickel composites. In the present study, Ni/Al2O3–13 wt-%TiO2 coatings have been electrodeposited using physically mixed commercial Al2O3 and TiO2 powders. The microhardness, wear and corrosion resistant properties of the coatings have been investigated. It was found that the area fraction of particles incorporated in the nickel matrix was very high at lower current density, and the corresponding composite coating exhibited a maximum microhardness (∼580 HK). Interestingly, corrosion resistance of Ni/Al2O3–13 wt-%TiO2 composite coating was similar to that reported for Ni/TiO2. The wear behaviour of Ni/Al2O3–13 wt-%TiO2 coating was in between Ni/Al2O3 and Ni/TiO2 coatings and thus exhibited a synergistic effect of the properties of Al2O3 and TiO2 powders.