Electrodeposition of bright nickel coating under perturbation of hard particles

Bright nickel was produced by a new electroforming technique with spherical hard particles filling between the electrodes. The related theories and the structure of the bright deposit were studied. It was found that the hard particles could increase the brightness of nickel deposits by perturbing the process of crystal nucleation and polishing the cathode surface during electrodepositing. A mathematical model about brightening effects of hard particles was constructed. A sound smooth nickel deposit, which was nearly mirror-bright, was electroformed by the presented technique. The analyses of transmission electron microscope (TEM) and X-ray diffraction (XRD) showed that the grain size was less than 80 nm and the deposit revealed a (2 0 0) preferential orientation.