Synthesis and characterization of nickel–diamond nanocomposite layers

Electrodeposition can be used in order to prepare nanocomposite coatings made of nanoparticles dispersed into a metallic matrix, onto a metallic substrate. These kinds of coatings can combine the properties of the matrix and of the dispersed nanoparticles, which can lead to some interesting properties of the mixture. Including diamond nanoparticles into a metallic matrix can take advantage of the diamond properties, especially of its hardness and inertness in many chemical media. Still, the proper control of the electrodeposition parameters is a must in order to obtain the best microhardness and corrosion behavior of such nanocomposite coating. This paper proposes the comparative analysis between Ni/diamond nanocomposite coatings, prepared by electrodeposition, by varying several deposition parameters and the corresponding pure nickel coatings onto the same type of substrate, namely copper. Microstructural and morphological analysis of the two kinds of coatings are also performed and studied, along with microhardness measurements and corrosion resistance tests. It is concluded that specific electrodeposition technique and corresponding parameters must be used in order to prepare those Ni/diamond nanocomposite coatings with the best microhardness and best corrosion resistance.