Electrodeposition and characterisation of nanocrystalline Ni–Mo coatings

In the present study suitable plating conditions for electrodeposition of thick, crack-free coatings at moderate temperatures and current densities with reasonable current efficiency have been developed. Ni–Mo coatings (5–22 wt.% Mo) were electrodeposited on steel substrates from sulphate–citrate baths under controlled hydrodynamic conditions. The microstructure, residual stresses, adhesion, microhardness and wear resistance of the coatings, deposited at different current densities were examined. The tribological properties of compact and adherent Ni–Mo deposits obtained in optimum conditions were compared with the behaviour of the electrodeposited chromium coatings.