This paper studies effects of the composite particle infringement of ZnO/Cr2O3 on zinc rich ternary based

coating.The corrosion-degradation property in 3.5% NaCl was investigatedusing polarization technique. The structural

characteristics of the multilayer produce coatings were evaluated by scanning electron microscope (SEM) equipped with

an energy dispersive spectrometer (EDS). The mechanical response of the coated samples was studied using a diamond

base Dura –Scan) micro-hardness tester and a MTR-300 dry abrasive wear tester. The combined effect of the coatings

gave highly-improved performance on microhardness, corrosion and wear damage. This also implies that protection of

wind-energy structures in marine environments can be achieved by composite strengthening capacity

Fayomi, O. S. I

Inegbenebor, A.O.

Joseph, O. O

Olukanni, D. O.

Popoola, A. P. I.

Covenant University Repository

Experimental study and effect of particulate interference on the microhardness, wearand microstructural properties of ternary doped coatingO. S. I. Fayomi, A. P. I. Popoola, O. O. Joseph, A. O. Inegbenebor, and D. O. Olukanni  Citation: AIP Conference Proceedings 1758, 020017 (2016); doi: 10.1063/1.4959393 View online: http://dx.doi.org/10.1063/1.4959393 View Table of Contents: http://scitation.aip.org/content/aip/proceeding/aipcp/1758?ver=pdfcov Published by the AIP Publishing  Articles you may be interested in Effect of pulse frequency on microstructural, nanomechanical, and wear properties of electrodeposited Ni–TiNcomposite coatings J. Appl. Phys. 116, 234302 (2014); 10.1063/1.4904190  Experimental study the effect of speeds in wear using fourball tribotester AIP Conf. Proc. 1440, 226 (2012); 10.1063/1.4704221  Magnetic properties and microstructure of FePt / Ag 2 Te particulate films J. Appl. 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Olukanni 3  1Department of Chemical, Metallurgical & Materials Engineering, Tshwane University of Technology, Pretoria, South Africa 2Department of Mechanical Engineering, Covenant University, P.M.B. 1023, Canaanland, Ota, Nigeria 3Department of Civil Engineering, Covenant University, P.M.B. 1023, Ota, Ogun State, Nigeria  * ojosundayfayomi3@gmail.com Abstract.This paper studies effects of the composite particle infringement of ZnO/Cr2O3 on zinc rich ternary based coating.The corrosion-degradation property in 3.5% NaCl was investigatedusing polarization technique. The structural characteristics of the multilayer produce coatings were evaluated by scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS). The mechanical response of the coated samples was studied using a diamond base Dura –Scan) micro-hardness tester and a MTR-300 dry abrasive wear tester.  The combined effect of the coatings gave highly-improved performance on microhardness, corrosion and wear damage. This also implies that protection of wind-energy structures in marine environments can be achieved by composite strengthening capacity. INTRODUCTION The challenge of component during service as a result of mechanical degradation and chemical deterioration is no news a concern to materials expert, in such a way that it affects both the domestic, industrial and national development [1]. Corrosion scientists and engineers are continually seeking for techniques and methods to effectively combat corrosion by learning the phenomenon and its control with the aim of finding better ways of using engineering materials.The failure of this materials are majorly in application like construction, aerospace, automobile, solar cells, ship building, and energy conservative. With the increasing way to oppose this catastrophic, promising methods of mitigation had been employed ranging from vapour deposition, laser coating, cold spray coating and so on. Surface enhancement of engineering materials is necessary for preventing service failures and corrosion attack in industry [1, 2].Electrodeposition technique had been proved to give superior advantages due to cost effectiveness, processing and nature of characteristics.  Zinc coatings add corrosion resistance to steel in several ways [4]. As a barrier layer, a continuous zinc coating separates the steel from the corrosive environment. The sacrificial properties of zinc can be seen in a galvanic series where the potential of zinc is less noble than steel in most environments at ambient temperatures. Zinc, like all metals, corrodes when exposed to the atmosphere. Infringement of particulate into bath rich such as zinc-composite had been seen as a promising way of getting better performance in term of corrosion protection, wear resistance and other metallurgical properties [5-7]. Hence, this paper focuses on the effects of Cr2O3 particulates on the morphology of the composite coatings. The hardness and corrosion resistance of the Zn-ZnO-Cr2O3 coatings are also evaluated. Technologies and Materials for Renewable Energy, Environment and SustainabilityAIP Conf. Proc. 1758, 020017-1–020017-6; doi: 10.1063/1.4959393Published by AIP Publishing. 978-0-7354-1416-7/$30.00020017-1 Reuse of AIP Publishing content is subject to the terms at: https://publishing.aip.org/authors/rights-and-permissions IP:  80.248.0.226 On: Tue, 26 Jul 2016 13:54:19EXPERIMENTAL SECTION Preparation of substrate Flat steel specimens of dimension (30 mm x 20 mm x 1 mm) sheet were used as the substrate and zinc sheets of (40 mm x 30 mm x 2 mm) were prepared as the anodes. The initial surface preparation was performed using progressively finer grades of emery paper, as described in our earlier publications [3, 4]. The samples were properly cleaned with sodium carbonate, pickled and activated with 5% HCl at ambient temperature for 10 seconds, followed by instant rinsing in deionized water. The specimens were obtained from Metal Sample site, Nigeria. The chemical composition of the sectioned samples analyzed on a spectrometer were C 0.15%, Mn 0.45%, Si 0.18%, P 0.01%, S 0.031%, Al 0.005%, Ni 0.008%, Fe Balance.  Formation of deposited coating The prepared Zn-ZnO-Cr2O3 composite bath was heated for 2hrs and stirred intermittently to obtain a clear solution before it was prepared for electrolytic deposition on the steel. The prepared cathode and anodes were connected to the D.C. power supply through a rectifier as described by [3, 4]. Deposition was carried out at varying applied current density around 1.0A/cm2 for 15 minutes. The distance between the anode and the cathode and the immersion depth were kept constant. Thereafter, the samples were rinsed in water and then dried. The formulated design plan for the coating is described in Table 1. TABLE 1: Formulated designed bath composition ofZn-ZnO-Cr2O3  Structural characterization of the coatings  The structural studies and elemental analysis of the fabricated alloy samples were verified using a high-tech TESCAN scanning electron microscope with an attached energy dispersive spectrometer (SEM/EDS).  RESULTS AND DISCUSSION Surfacemorphology Figure 1a and b shows the structural properties of Zn-8ZnO and Zn-8ZnO-16gCr2O3 composite coating respectively. The EDS pattern of the composite coating confirms the crystalline phase of the film as identified in Figure 2. The nano particulates were found to be agglomerated when analyzed by scanning electron microscopy (Figure 1a) studies. This is due to the high surface energy of the particles. In general it can be seen that the coating on the mild steel plate resulted into a good appearance, better plating and good adhesion. The nature of the surface morphology and orientation in Figure 1b revealed the non- homogeneous appearance but good dispatches as expected. There are no pores and cracks at the interface, which shows that the interface bonding is firm. But the observed improvement may not be far from the possibility that the deposition behaviour and the adhesion strength of any particular plating often based on the current density, potential, plating time and strengthening effect of the grain present in the matrix [5] Figure 2 revealed the morphology of the coating, indicate fine grain size, uniform arrangementandcrystalgrowthfortheZn-8ZnO-16gCr2O3 coating.UnliketheZn-8ZnO depositionwheregood surfacedeposition was achieved but irregularor inhomogeneous dispersion of deposit wasobserved.     Sample order Matrix Sample  Time of deposition (min) Current density(A/cm2) 1 Zn-8ZnO 15 1.0 2 Zn-8ZnO-16Cr2O3 15 1.0 020017-2 Reuse of AIP Publishing content is subject to the terms at: https://publishing.aip.org/authors/rights-and-permissions IP:  80.248.0.226 On: Tue, 26 Jul 2016 13:54:19  FIGURE1.SEM images of the a) Zn-8ZnO and b) Zn-8ZnO-16gCr2O3 composite coating  FIGURE 2. Energy Dispersive Spectral Zn-8ZnO-16gCr2O3 hybrid  Wear and Microhardness property Figure4showsthewearlossofZn -ZnO coating andZn-ZnO-Cr2O3composite coatings with differentCr2O3 contents.Itis obviousthat the wearresistance ofthe compositecoatings is morethanthatof Zn -ZnO coating. Thoughthe wearresistance of the compositecoatings did not increasewith increase inthe Cr2O3 particlescontent, as it can be seen that Zn-ZnO-8Cr2O3 displayed the optimum wear resistance, but the addition of Cr2O3 in the matrix has immensely contributed to the wear resistance. The thermal deformations were observed in 250oC for 4hrs and mechanical responses of the coated samples were investigated. A goodincrease inthemicro hardnessvaluewasobservedintheZn-ZnO-Cr2O3composite coating even before heat-treatment asshowninFigure3.The microhardness valuefor theZn -ZnOmaterialwas134.0 HVN and almost doubled for the value ofZn-8ZnO-8Cr2O3compositecoating (which was the optimal performance) with344HVN. Figure 4 illustrates the wear analysis of the coatings. The improved wear resistance canbeattributedtothe strengtheningeffect. The hardness process parameterand microstructural behaviourare theparameterswhichaffectthewear resistance as indicated by [6]. The wear resistance increases with 020017-3 Reuse of AIP Publishing content is subject to the terms at: https://publishing.aip.org/authors/rights-and-permissions IP:  80.248.0.226 On: Tue, 26 Jul 2016 13:54:19increasinghardnessof the matrix. The tendency of Zn-ZnO-Cr2O3composite coatings for plastic deformationislessthan Zn - ZnO coating. The resultssuggestthatthewearresistancewas improvedby the addition of Cr2O3 particles. According to [7], the embeddedCr2O3 particles cansignificantlyimprove thetribological performanceof Zn-ZnO-Cr2O3composite coatings. Figure 3 show the Microhardness variation of the nano-composite coating before heat treatment. The increase inhardnessof the Zn-ZnO-Cr2O3composite coated specimens was dueto thepresenceof theCr2O3as reinforcement additive, despite the fact that the increase in the quantity has limit.  125 130.5 020406080100120140Zn-8ZnO Zn-8ZnO-16Cr2O3Microhardness (HVN) Coating Matrixes Average FIGURE 3.Variation ofhardness propertywith coating matrix. 0.0180.00800.0050.010.0150.020.025Zn-8ZnO Zn-8ZnO-16Cr2O3Wear (g/min)Coating MatrixesAverage FIGURE 4.Variation ofwear rate with time.  020017-4 Reuse of AIP Publishing content is subject to the terms at: https://publishing.aip.org/authors/rights-and-permissions IP:  80.248.0.226 On: Tue, 26 Jul 2016 13:54:19Polarization measurements The values of Ecorr, jcorr, corrosion rate (CR) and polarization resistance (RP) of the samples before heat-treatment are extrapolated from tafel slope as presented in Table 2. The results revealed the corrosion resistance behaviour of the coatings in 3.65% NaCl static solution. From the polarization curves of Zn-ZnO-Cr2O3 composite coating in Figure 5, it was found that the addition of Cr2O3 altered the shape of the polarization curve but causes a considerable increase in the value of the Ecorr. The features from the linear polarization test (Figure 5) indicate that an increase in additive concentration intensifies this process. However, the optimal value for the coating with least corrosion rate was Zn-8ZnO-8Cr2O3, which implies that addition of Cr2O3 gives better effect of corrosion resistant property. According to [9], this could be attributed to the nature and tenacity of the passive film produced by Zn-8ZnO-8Cr2O3 on the surface of the coated steel and the drop in the potential thereafter could be traced to slight passivity breakdown experienced when the concentration of Cr2O3 was further increased, which is in line with [8].  0.853 0.854 0.855 0.856 Zn-8ZnO Zn-ZnO-16Cr2O3Corrosion rate (mm/yrs)Fabricated CoatingsCR (mm/year)784 FIGURE 5.Potentiodynamic polarization curves o Zn-ZnO-Cr2O3 composite coating on mild steel in 3.65%NaCl solution.  TABLE2: Polarization data extrapolated from Tafel slope for matrix Zn-ZnO-Cr2O3 composite coating. Samples No Ecorr,Obs (V) jcorr (A/cm²) CR (mm/year) Rp (Ω) 1. Zn-8ZnO -1.3067 0.003029 0.854270 23.583 2.Zn-ZnO-16Cr2O3 -1.3706 0.003102 0.856890 20.390 020017-5 Reuse of AIP Publishing content is subject to the terms at: https://publishing.aip.org/authors/rights-and-permissions IP:  80.248.0.226 On: Tue, 26 Jul 2016 13:54:19CONCLUSIONS The following conclusions were drawn from the study: 1. Composite coatings consisting of Zn-ZnO and Zn-ZnO-Cr2O3particles weresuccessfully prepared by means of an electro-depositiontechniqueonto carbon steel substrates. 2. The plating of Zn with incorporation ZnO and Cr2O3in the coating was confirmedby the EDS and XRD. 3. The co-deposition of nano-sized Cr2O3 particles in a metal deposit modified the surface morphology of the substrate. 4. The developed composite coating was mechanically and thermally stable. 5. The presence of Cr2O3 particles in the matrix of the coating system increased adhesion, corrosion resistance and micro-hardness of the surface, compared to that of plain carbon steel. ACKNOWLEDGEMENT This material is based upon work supported financially by the National Research Foundation.  The authors acknowledge the support from Surface Engineering Research   Centre, (SERC) Tshwane University of Technology Pretoria, South Africa. REFERENCES 1. M. J. Rahman,S. R. Sen, M. Moniruzzaman and K. M. Shorowordi, J. Mech. Eng. 40, 9-14 (2009). 2. B. M. Praveen, T. N. Venkatesha, Y. ArthobaNaik, and K. Prashantha, Surf. Coat. Tech. 201, 5836-5842 (2007). 3. A. P. I. Popoola, O. S. I. Fayomi and O. M. Popoola, Int. J. Electrochem. Sci. 7, 4898–4917 (2012). 4. O. S. I. Fayomi, V. R. Tau, A. P. I. Popoola, B. M. Durodola, O. O. Ajayi, C. A. Lotoand O. A. Inegbenebor, J. Mater. Environ. Sci.3, 271-280 (2011). 5. L. E. Umoru, I. A. Fawehinmiand A. Y. Fasasi, J. Appl. Sci. Res. 2, 200-204 (2006). 6. E. A. Noor and A. H. Al-Moubaraki, Int. J. Electrochem. Sci. 3, 806-818 (2008). 7. A. P. I.PopoolaandO. S. Fayomi, Int. J. of thePhy.Sci. 6, 2447-2454 (2011). 8. O. S. I. Fayomi, A. P .I. Popoola, C. A. Loto and S. T. Adedokun, Protection of Metals and Physical Chemistry of Surfaces. 52, 238–243 (2016). 9. J. Winiarski, A. Leśniewicz, P. Pohl and B. Szczygieł, Surface & Coatings Technology.299, 81–89 (2016). 020017-6 Reuse of AIP Publishing content is subject to the terms at: https://publishing.aip.org/authors/rights-and-permissions IP:  80.248.0.226 On: Tue, 26 Jul 2016 13:54:19

Experimental Study and Effect of Particulate Interference

on the Microhardness, Wear and Microstructural Properties

of Ternary Doped Coating

O. S. I. Fayomi

A. P. I. Popoola

O. O. Joseph

A. O. Inegbenebor

D. O. Olukanni

Crossref

Experimental study and effect of particulate interference on the microhardness, wear and microstructural properties of ternary doped coating

http://eprints.covenantuniversity.edu.ng/7094/1/Experimental%20study%20and%20effect%20of%20particulate%20interference%20on%20the%20microhardness%2C%20wear_AIP%20conf.%20proceeds.pdf

Experimental Study and Effect of Particulate Interference on the Microhardness, Wear and Microstructural Properties of Ternary Doped Coating

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