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.

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► The nano-sized ceria, produced by HEBM technique, co-electrodeposited successfully in the nanocrystalline nickel matrix.
► The (1 1 1) fiber texture is predominant over (2 0 0) fiber in the sample prepared with 9% duty cycle.
► The crystallite size changes from micrometer to nanometer range as the duty cycle increases from 6 to 9 or 17%.
► The microhardness of the nanocomposite coating increases with the increase in the duty cycle.