Electrodeposition of Ni–Co/nano Al2O3 composite coating on low carbon steel and its characterization
Mazen Kamel, Z. Abdel Hamid, S.M. Rashwan, I.S. Ibrahim, S.M. El Sheikh, Mazlan Mohamed
Abstract
Ni–Co / nano-Al 2 O 3 composite coat was electrodeposited from environmentally friendly citrate tub. The electrodeposition was established from agitated solutions, containing disparate amounts of nano-Al 2 O 3 particles. The addition of nano - Al 2 O 3 to the plating solution decreases the polarization for Ni–Co alloy plating. The quantity of Al 2 O 3 in the composite rises with concentration of Al 2 O 3 in the coating solution, current density and decreasing temperature. Composites were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X – ray (EDX) techniques. The obtained composites were crystalline and had face-centered cubic (FCC) structure. The thickness of composite diminishes with increasing the amount of Al 2 O 3 in the composite however, the microhardness increases. The resistance of Ni–Co / nano-Al 2 O 3 composite against corrosion in 3.5 % salt water was tested by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Ni–Co/nano-Al 2 O 3 composites had a good corrosion resistance.