The electrodeposition of nanocrystalline Cobalt–Nickel–Phosphorus alloy coatings: a review

Abstract

The importance of Co–Ni–P alloy deposits is summarised and recent developments are highlighted. Electroplating and electroless deposition of nanocrystalline Co–Ni–P ternary coatings are considered. Nanostructure, physical and mechanical properties (including corrosion resistance) of various bath types and compositions (including pH and electrolyte additives) as well as plating conditions (including current density, temperature and agitation) are summarised. Applications range from wear and corrosion resistant coatings, particularly as a hard chromium replacement to speciality hydrogen evolution electrodes in water electrolysis. Following this concise review, future research needs are briefly listed.

Keywords:

• Alloy deposits
• Corrosion resistance
• Electrocrystallisation
• Electron diffraction
• Electroplating
• Hardness
• Nanostructure
• Nickel phosphides
• Transmission electron microscopy