Electrodeposition and characterization of Ni–Y2O3 composite

Nano-sized Y2O3 particles were codeposited with nickel by electrolytic plating from a nickel sulfate bath. The effects of the incorporated Y2O3 on the structure, morphology and mechanical properties (including microhardness, friction coefficient and wear resistant) of Ni–Y2O3 composite coatings were studied. It is observed that the addition of nano-sized Y2O3 particles shows apparent influence on the reduction potential and pH of the electrolyte. The incorporated Y2O3 increases from 1.56 wt.% to 4.4 wt.% by increasing the Y2O3 concentration in the plating bath from 20 to 80 g/l. XRD results reveal that the incorporated Y2O3 particles favour the crystal faces (2 0 0) and (2 2 0). SEM and AFM images demonstrate that the addition of Y2O3 particles causes a smooth and compact surface. The present study also shows that the codeposited Y2O3 particles in deposits decrease the friction coefficient and simultaneously reduce the wear weight loss. Ni–Y2O3 composite coatings reach their best microhardness and tribological properties at Y2O3 content 4.4 wt.% under the experiment conditions.