Effect of Electrolyte Temperature on Properties of Nickel Film Coated onto Copper Alloy Fabricated by Electroplating

Nickel and nickel-based alloys as protective coatings are used in various applications where the corrosion resistance is required. They have been widely used in automotive, aircraft, marine, nuclear power plant, oil, and gas industries. This work aims at fabricating nickel layers on copper alloy substrates through electroplating techniques with different electrolyte temperatures (20, 30, and 50 degrees C). The effect of the electrolyte temperature on the electroplated nickel layers was investigated by using a field emission scanning electron microscope, an X-ray diffraction (XRD), a potentiostat, a camera, and a microhardness test. It is expected that electrolyte temperatures could influence the surface morphology, crystallographic orientation, the electrochemical behavior, wettability, and the hardness of the nickel layers. The surface morphology shows differences in terms of the roughness and the grain size for various samples. Raising the electrolyte temperature from 20 to 50 degrees C results in the increase of the water contact angles and the decrease in the hardness of the Ni layers, while the crystallite size has a maximum value at 30 degrees C. Moreover, the different XRD intensity from the (111) planes shows a significant influence on the corrosion resistance.