Electrodeposition and Characterization of Ni–Cr Alloy Coating

Abstract

Simultaneous deposition of both nickel and chromium in the form of alloy is a subject with pronounced practical significance in automobile industries. Electroplating of Ni–Cr alloy has been carried out using suitable plating bath solution and working conditions. The alloys are partially crystalline and new phases appear on heat-treatment of the coating. Surface morphology and microstructure of the coating are closely related to the nature of the bath components, bath composition, alloy composition, and post-treatment of the coating. X-ray photoelectron spectroscopy studies indicated that the alloy contains nickel in and oxidation states, whereas it contains chromium in the oxidation state in the deposited Ni–Cr coating. The sputtering of the coatings up to changed the nickel and chromium to metallic state. The coated alloys exhibited good corrosion resistance to acidic media, e.g., , HCl, and 5% NaCl (pH 5), and heat-treatment of the coating enhanced the corrosion resistance.