Preparation and characterization of jet-electrodeposited nanocrystalline nickel coatings

Nanocrystalline nickel coatings were prepared by both direct current(DC) and pulse current(PC) jet-electrodeposition. The influences of current density and jet velocity on the surface morphology,microstructure and preferred orientation of the coatings obtained were investigated by SEM,TEM and XRD. It is found that the current density strongly affects the microstructure of the nickel coating. An increase of the DC current density results in a slight increase of the grain size and preferred orientation progressive evolution(i.e. from(111) to(200)),whereas an increase of the PC current density leads to a certain decrease of the grain size and preferred orientation change(i.e. from(111) to a strong(220)). Moreover,jet velocity shows no significant effect on the grain size and preferred orientation for the nanocrystalline coatings obtained in both DC and PC within the range of jet velocity studied.