Nano-nickel–copper alloy deposit for improved corrosion resistance in marine environment

The nickel–copper alloy (70:30) prepared by metallurgical route is currently employed in marine environments because of its good resistance to corrosion. This alloy forms a thin protective surface layer when exposed to marine atmosphere and thus provides its corrosion resistance. Electrodeposition of nickel–copper alloy from sulphamate acetate-based electrolyte is a new and novel approach and was experimented. The detailed study was performed on the effect of electrolyte composition, current density and pH on the preparation of alloy deposit; the prepared alloy deposit particle size is of 78 nm, and the surface morphology of the alloy deposit was characterized with X-ray diffraction, scanning electron microscopy, EDAX, and atomic force microscope. Nickel–copper alloy deposited from the sulphamate acetate-based electrolyte operated at a temperature of 30 °C, with a pH of 6.6 and at 3 A/dm², produces nickel– copper (70:30) alloy deposit. The corrosion behaviour of this alloy deposit was studied by potentiodynamic polarization method; the corrosion current of nickel is 8.67 μA cm^-2 and the nickel–copper alloy is 2.65 μA cm^-2.

Keywords
Nickel–copper alloy deposition; Nanonickel– copper alloy coating; Corrosion protection alloy; Marine protection coating