Improvement in Mechanical Properties of Mild Steel by Zn-Co-Ni Coating at Different Co Concentrations

Abstract

Zn-Co-Ni alloy was deposited on mild steel substrate prepared by electrochemical deposition method using sulfate bath. The effect of Co concentration on the surface morphology, microstructure, crystal structure, Vicker’s hardness and mechanical properties were studies. Deposition was carried out at suitable working parameters such as temperature, current density, pH and deposition time. Magnetic field was used for coating smoothness and enhancing deposition rate. X-ray diffraction, scanning electron microscopy and mechanical properties were used to investigate the crystal structure, surface morphology and microhardness respectively. The result shows that, when increasing the Co concentration, the microhardness, ultimate tensile strength, yield stress and elastic modulus increased and elongation of Zn-Co-Ni alloy is decreased. Micrographs shows that, globular like morphology change into smooth morphology by increasing the Co concentration. The lattice parameter is decreased by increasing Co concentration. Result also shows that substrate become more applicable by deposition.