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COMPOSITES AND MULTIPURPOSE COATINGS
ArticleName Composition, morphology and tribological properties of PEO-coatings formed on an aluminum alloy D16 at different duty cycles of the polarizing signal
DOI 10.17580/nfm.2017.01.03
ArticleAuthor Egorkin V. S., Vyaliy I. E., Sinebryukhov S. L., Gnedenkov S. V.
ArticleAuthorData

Institute of Chemistry of Far Eastern Branch of Russian Academy of Sciences, Vladivostok, Russia:

V. S. Egorkin, Senior Researcher of Laboratory of Nonstationary Surface Processes, е-mail: egorkin@ich.dvo.ru
I. E. Vyaliy, Junior Researcher of Laboratory of Nonstationary Surface Processes
S. L. Sinebryukhov, Associate Professor; Head of Laboratory of Nonstationary Surface Processes
S. V. Gnedenkov, Dep. Director for Science; Head of the Department of Electrochemical Systems and Surface Modification Processes

Abstract

The paper presents the results of a study of the chemical composition, morphology, and tribological properties of coatings produced on an aluminum alloy D16 in a tartrate-containing electrolyte by plasma electrolytic oxidation (PEO). In order to form the coatings, a transistor power supply was used, providing a 5 s square-wave voltage pulses to the treated sample. The power supply is capable to control the pauses between pulses to achieve the required duty cycle values D. The influence of the parameters of the polarizing signal and the time of oxidation on the properties of the obtained PEO coatings is studied. It is established that the change in the duty cycle of the polarizing signal affects the chemical composition, thickness and properties of the formed oxide coatings. The results of X-ray diffraction data indicate that the main component of the PEO layers under investigation is a cubic modification of aluminum oxide (γ-Al2O3). In addition to cubic, the -alumina (β-Al2O3), aluminum phosphate (AlPO4) and molybdenum and aluminum carbide (Al2Mo3C), which are formed as a result of plasma-chemical reactions involving the processed alloy and electrolyte components, are also present in the PEO layers. The analysis of the dependence of the friction coefficient  on the number of cycles shows that the PEO coatings formed at larger values of the duty cycle and oxidation time can withstand substantially more abrasion cycles. With the increase in the amount of electricity consumed to create the coating, thicker PEO layers are formed, which contributes to the improvement of tribological properties. It is established that an increase in the duty cycle of the polarizing signal leads to the reduction of the apparent porosity of the formed PEO layers, formation of more aluminum and molybdenum carbides in their composition, which leads to an increase in the wear resistance and hardness of the coatings.

This work was supported by the Russian Science Foundation (No. 14-33-00009).

keywords Plasma electrolytic oxidation, microsecond pulses, aluminum, protective coatings, microhardness, duty cycle, friction coefficient
References

1. Dehnavi V., Luan B. L., Shoesmith D. W., Liu X. Y., Rohani S. Effect of duty cycle and applied current frequency on plasma electrolytic oxidation (PEO) coating growth behaviour. Surface and Coatings Technology. 2013. Vol. 226. pp. 100–107.
2. Gnedenkov S. V., Egorkin V. S., Sinebryukhov S. L., Vyaliy I. E. Electrochemical properties of oxide coatings on AMg3 (AMг3) aluminium alloy, treated with hydrophobic agent solution. Tsvetnye Metally. 2015. No. 8. pp. 55–60.

3. Du K., Guo X., Guo Q., Wang F., Tian Y. A monolayer PEO coating on 2024 Al alloy by transient self-feedback control mode. Materials Letters. 2013. Vol. 91. pp. 45–49.
4. Matykina E., Arrabal R., Pardo A., Mohedano M., Mingo B., Rodríguez I., González J. Energy-efficient PEO process of aluminium alloys. Materials Letters. 2014. Vol. 127. pp. 13–16.
5. Guan Y., Xia Y., Li G. Growth mechanism and corrosion behaviour of ceramic coatings on aluminum produced by autocontrol AC pulse PEO. Surface and Coatings Technology. 2008. Vol. 202. pp. 4602–4612.
6. Gao Y., Yerokhin A., Matthews A. Effect of current mode on PEO treatment of magnesium in Ca- and P-containing electrolyte and resulting coatings. Applied Surface Science. 2014. Vol. 316. pp. 558–567.
7. Sinebryukhov S. L., Sidorova M. V., Egorkin V. S., Nedozorov P. M., Ustinov A. Yu., Volkova E. F., Gnedenkov S. V. Protective oxide coatings on Mg – Mn – Ce, Mg – Zn – Zr, Mg – Al – Zn – Mn, Mg – Zn – Zr – Y, and Mg – Zr – Nd magnesium-based alloys. Protection of Metals and Physical Chemistry of Surfaces. 2012. Vol. 48, No. 6. pp. 678–687.
8. Liu Y., Yang F., Zuo G., Zhang Z. Plasma electrolytic oxidation of AZ91D magnesium alloy in biosafety electrolyte for the surgical implant purpose. Russian Journal of Electrochemistry. 2013. Vol. 49, No. 10. pp. 987–993.
9. Gnedenkov S. V., Egorkin V. S., Sinebryukhov S. L., Vyaliy I. E., Pashinin A. S., Emelyanenko A. M., Boinovich L. B. Formation and electrochemical properties of the superhydrophobic nanocomposite coating on Mg–Mn–Ce magnesium alloy. Surface and Coatings Technology. 2013. Vol. 232. pp. 240–246.
10. Hussein R. O., Zhang P., Nie X., Xia Y., Northwood D. O. The effect of current mode and discharge type on the corrosion resistance of plasma electrolytic oxidation (PEO) coated magnesium alloy AJ62. Surface and Coatings Technology. 2011. Vol. 206. pp. 1990–1997.
11. Gnedenkov S. V., Sinebryukhov S. L., Egorkin V. S., Vyaliy I. E., Emelyanenko A. M., Boinovich L. B. Protective properties of the nanocomposite coatings on Mg alloy. Solid State Phenomena. 2014. Vol. 213. pp. 176–179.
12. Hussein R. O., Northwood D. O., Nie X. The influence of pulse timing and current mode on the microstructure and corrosion behaviour of a plasma electrolytic oxidation (PEO) coated AM60B magnesium alloy. Journal of Alloys Compounds. 2012. Vol. 541. pp. 41–48.
13. Gnedenkov S. V., Sinebryukhov S. L., Puz’ A. V., Gneden kov A. S., Vyaliy I. E., Mashtalyar D. V., Egorkin V. S. Plasma electrolytic oxidation coatings formed with microsecond current pulses. Solid State Phenomena. 2014. Vol. 213. pp. 149–153.
14. Hussein R. O., Nie X., Northwood D. O. A spectroscopic and microstructural study of oxide coatings produced on a Ti – 6Al – 4V alloy by plasma electrolytic oxidation. Materials Chemistry and Physics. 2012. Vol. 134. pp. 484–492.
15. Hussein R. O., Nie X., Northwood D. O. An investigation of ceramic coating growth mechanisms in plasma electrolytic oxidation (PEO) processing. Electrochimica Acta. 2013. Vol. 112. pp. 111–119.
16. Ribeiro A. A., Vaz L. G., Guastaldi A. C., Campos J. S. C. Adhesion strength characterization of PVDF/HA coating on cp Ti surface modified by laser beam irradiation. Applied Surface Science. 2012. Vol. 258. pp. 10110–10114.
17. Rudnev V. S., Yarovaya T. P., Nedozorov P. M., Ustinov A. Yu., Tyrina L. M., Malyshev I. V., Kuryavyi V. G., Egorkin V. S., Sinebryukhov S. L., Gnedenkov S. V. Obtaining ZrO2 + CeOx + TiO2/Ti compositions by plasma electrolytic oxidation of titanium and investigating their properties. Protection of Metals and Physical Chemistry of Surfaces. 2011. Vol. 47, No. 5. pp. 621–628.
18. Rudnev V. S., Yarovaya T. P., Egorkin V. S., Sinebryukhov S. L., Gnedenkov S. V. Properties of coatings formed on titanium by plasma electrolytic oxidation in a phosphate-borate electrolyte. Russian Journal of Applied Chemistry. 2010. Vol. 83, No. 4. pp. 664–670.
19. Wang Y. L., Wang M., Zhou M., Jiang Z. H. Characterization of graphite containing ceramic coating prepared on carbon steel by plasma electrolytic oxidation. Applied Mechanics and Materials. 2012. Vol. 271/272. pp. 46–49.
20. Egorkin V. S., Vyaliy I. E., Sinebryukhov S. L., Gnedenkov S. V., Bouznik V. M. Effect of Polarizing Signal Duty Cycle on the Composition, Morphology, and Protective Properties of PEO Coatings on AMg3 Aluminum Alloy. Inorganic Materials. 2016. Vol. 52, No. 4. pp. 405–411.
21. Locke B. R., Thagard S. M. Analysis of chemical reactions in gliding-arc reactors with water spray into flowing oxygen. IEEE Transactions on Plasma Sciences. 2009. Vol. 37, No. 4. pp. 494–501.

Full content Composition, morphology and tribological properties of PEO-coatings formed on an aluminum alloy D16 at different duty cycles of the polarizing signal
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