Characterization of Nanocrystalline NiP Alloy Coatings Electrodeposited at Various Current Densities

Abstract

Nickel phosphorus alloy coatings were prepared by electrodeposition route from sulfate electrolyte bath at various current densities. SEM studies revealed that spherical grains covered the entire surface with uniform distribution. EDX results showed a linear increase of P content in the developed deposits with current density, causing an increase in the grains size and a drop in hardness values. XRD studies revealed monocrystalline orthorhombic alloys at low phosphorus content (10.88 wt. %). Corrosion test results showed that 1 A.dm-2 is the best applied current density providing the nobler Ecorr (-171.4 mV) and the lower icorr (4.64 μA/cm2).