Evolution of physical and mechanical characteristics of deposited composite coatings on A356 mild steel

Fayomi, O. S. I and Oluwadare, G. A. and Fakehinde, O. B and AKANDE, I.G and Nwachia, W. and Russell, A. J. (2019) Evolution of physical and mechanical characteristics of deposited composite coatings on A356 mild steel. The International Journal of Advanced Manufacturing Technology.

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Abstract

This research investigated the development of Zn-SnO2/Zn-Al2SiO5 thin film on A356 mild steel using the electrodeposition technique. The developed coating was attained in 2.0 V for 10 min at a constant current density of 1.5 A/cm2. The electroplating process was maintained at a constant stirring rate of 250 rpm, temperature of 45 °C, 10 g of SnO2 was used for the bath while Al2SiO5 was varied from 5 to 15 g. The surfaces of coated samples were characterized using a scanning electron microscope (SEM). The effects of 3.56% NaCl on the coated and uncoated sample were examined via the potentiodynamic polarization technique, employing Autolab PGSTAT 101 Metrohm potentiostat with NOVA software of version 2.1.2. The outcome of the experiment revealed that the electrodeposited Zn-SnO2/Zn-Al2SiO5 exhibits better stability, improved microhardness, excellent microstructural qualities, and outstanding corrosion resistance. The Zn-10SnO2-15Al2SiO5-coated steel exhibits the lowest corrosion rate of 0.0473 mm/year, representing 99.32% reduction in corrosion rate compared to the uncoated sample. Similarly, a corrosion current density (jcorr) value of 20.5 μA/cm2 was recorded for the uncoated sample which is much greater than the jcorr of the coated samples. This shows that the coating minimizes the exchange of current within the steel. The hardness value of the Zn-10SnO2-15Al2SiO5-coated steel was higher than other coated samples and 17.51% higher than the uncoated steel, and this indicates improvement in the mechanical property of the steel.

Item Type:	Article
Uncontrolled Keywords:	Characterization . Coating . Electroplating . Mild steel
Subjects:	T Technology > T Technology (General) T Technology > TJ Mechanical engineering and machinery
Divisions:	Faculty of Engineering, Science and Mathematics > School of Engineering Sciences
Depositing User:	Mrs Hannah Akinwumi
Date Deposited:	24 Jun 2019 09:16
Last Modified:	24 Jun 2019 09:16
URI:	http://eprints.covenantuniversity.edu.ng/id/eprint/12761

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