Influence of duty cycle on the microstructure and microhardness of pulse electrodeposited Ni-CeO2 nanocomposite coating

The Ni-CeO2 nanocomposite coatings have been synthesized by pulse electrodeposition technique with different duty cycles (6, 9 and 17%) from a Watts-type electrolyte containing nano-sized CeO2 particles. The XRD results show that the (2 0 0) orientation is dominant over (1 1 1) orientation in the Ni-CeO2 nanocomposite coatings prepared with 6 and 17% duty cycles, while the opposite is true for the sample prepared with 9% duty cycle. The maximum amount of CeO2 (10 wt%) incorporation in the coating occurs at 9% duty cycle. The crystallite size changes from micrometer to nanometer as the duty cycle changes from 6 to 9%. The hardness increases as the duty cycle increases from 6 to 17%. However, a coating with optimum smoothness and small number of microcracks is obtained at 9% duty cycle. (C) 2011 Elsevier Ltd. All rights reserved.