Corrosion Resistance of Electroless Ni-Cu-P Ternary Alloy Coatings in Acidic and Neutral Corrosive Mediums

Abstract EN

Electroless Ni-Cu-P alloy coatings were deposited on the ordinary steel substrate in an acidic hypophosphite-type plating bath.

These coatings were characterized by a scanning electron microscope (SEM) and an X-ray diffraction.

The micrograph shows that coating presents a nodular aspect and is relatively homogeneous and very smooth.

The EDX analysis shows that the coating contains 12 wt.% of phosphorus element with a predominance of nickel element.

In addition, the anticorrosion properties of the Ni-Cu-P coatings in 1 M HCl, 1 M H2SO4, and 3% NaCl solutions were investigated using Tafel polarization curves, electrochemical impedance spectroscopy, and SEM/EDX analysis.

The result showed a marginal improvement in corrosion resistance in 3% NaCl solution compared to acidic medium.

It also showed that the corrosion mechanism depends on the nature of the solution.