A study on the mechanism of formation of electrocodeposited Ni–diamond coatings

Co-deposition behavior of diamond particles and nickel onto a steel in nickel sulfamate baths has been investigated using both a rotating disc and wire geometries. Based on the zeta potential measurement and the change of diamond content of the deposits with electrical potential strength, diamond particles attracted to the cathode electrophoretically after adsorption of positive nickel ions. Results of polarization studies showed that since the rate of nickel deposition was controlled by both mass transfer of the nickel ions and electrochemical deposition, diamond content in nickel–diamond deposits decreased with increasing applied potential and stirring speed in the relatively high rotation speed ranges.