Electron Microscope Observations on Electrolytic Ni-Mo-Fe Coatings

SummarySelected Ni-Mo-Fe coatings were electrodeposited from ammoniacal citrate baths by varying the plating parameters. Their surfaces were examined by scanning electron microscopy for topography and SE imaging. Observed electrocatalytic, corrosion and optical properties of the coatings were found to be dependent on surface structure. The results were also used to understand the influence of electrodeposition variables. The plating diameters were found to have strong influence on the surface structure. Increases in deposition CD resulted in phase segregation in these materials. Also it was confirmed that increases in molybdenum content of the plating bath introduced heterogeneity in the plated samples with occurrence of more than one phase. Multinucleation in crystal structure was observed in samples electrodeposited at near neutral pH levels, again due to increased molybdenum content. The coatings reveal network formation at 300°C. Inclusion of Mn was helpful in obtaining homogeneous deposits.