HOW TO MAKE MAGNESIUM ALLOYS BE RESISTANT TO OPERATIONAL RISKS
https://doi.org/10.21122/2227-1031-2016-15-5-435-441
Abstract
The paper studies regularities and mechanisms of structure and phase formation in the surface layers of magnesium alloys when they are processed by method of micro-arc oxidation [MAO]. It has been determined that the same specific features of structure formation, namely: existence of a thin dense inner sublayer and a thicker outer sublayer with developed porosity are common for all types of coatings on the surface of magnesium and aluminum alloys. Such structural state of a protective coating can not be considered as a guaranteed protection against operational impacts, taking into account the fields of their primary application that is aviation construction, automotive construction, instrumentation, building construction, etc. The paper has analyzed the effect of alkaline electrolytes with varying chemical composition due to additions of sodium fluoride or potassium on the structure and properties of these alloys as well as on the level of basic performance characteristics of the layers formed in such electrolytes. On the basis of the analysis a conclusion has been made that it is possible to extend their life-span under operational conditions. It has been revealed that the existing techniques and methods for process control of MAO aluminum and magnesium alloys, particularly processing modes and technological equipment capacity determine a nature of structure formation and changes in a phase composition of the formed coatings.
About the Authors
N. M. Chigrinova
Belarusian National Technical University
Belarus
Belarus
Address for correspondence: Chigrinova Natalija M.— Belаrusian National Technical University, 67 Nezavisimosty Ave., 220013, Minsk, Republic of Belarus Tel.: +375 17 293-95-81 tiro@bntu.by
E. A. Vorobiova
Belarusian National Technical University
Belarus
Belarus
Undergraduate
V. E. Chigrinov
Belarusian National Technical University
Belarus
Belarus
References
1. Kazanski B., Kossenko A., Lugovskoy M. (2012) The Influence of Fluoride Additives on the Properties of Oxide Layer Produced by Plasma Electrolytic Oxidation. Defect and Diffusion Forum, 326–328, 498–503. DOI: 10.4028/www.scientific.net/DDF.326-328.498.
2. Wang Z., Wu L., Cai W., Shan A., Zhaohua J. (2010) Effects of Fluoride on the Structure ?nd Properties of Micro-arc Oxidation Coating on Aluminium Alloy. Journal of Alloys and Compounds, 505 (1), 188–193. DOI: http://dx. doi.org/10.1016/j.jallcom.2010.06.027.
3. Khokhlov V. V., Vavilkin N. M., Klevtsov A. G., Bautin V. A., Rakoch A. G., Kutyrev A. E., Magurova Yu. V. (2005) Method for Obtaining Protective Coatings on the Surface of Products Made from Magnesium and Magnesium-Based Alloys. Patent of Russian Federation No 2260078. (in Russian).
4. Vladimirov B. V. (2014) Influence of Electrolyte Composition on ??2-1-Alloy Properties During Micro-arc Oxidation. Izvestiia Tomskogo Politekhnicheskogo Universiteta [Proceedings of Tomsk Polytechnic University], 324 (2), 143–148 (in Russian).
5. Gnedenkov S. V., Khrisanfova O. A., Zavidnaya A. G., Sinebryukhov S. L., Egorkin V. S., Nistratova M. V. (2009) Method for Obtaining Protective Coatings While Using Magnesium Alloys. Patent of Russian Federation No 2357016. (in Russian).
6. Karimova S. A., Kozlov I. A., Pavlovskaya T. G. (2012) Method for Obtaining Protective Coatings While Using Magnesium Alloys. Patent of Russian Federation No 2447202. (in Russian).
7. Khla Mo. (2007) Optimization of Micro-arc Oxidation Process for Aluminium and Magnesium Alloys. Moscow. 133 (in Russian).
8. Hwang D. Y., Ko Y. G., Kim Y. M., Yoo B., Shin D. H. (2010) Influence of Post-Annealing on the Oxide Layer of AZ91 Mg Alloy Prepared by Plasma Electrolytic Oxidation. Materials Transactions, 51 (2), 408–412 DOI: 10. 2320/matertrans.M2009290.
9. Averyanov E. E. (1988) Anodizing Guide. Moscow, Mashinostroyenie, 81–82 (in Russian).
10. Khaselev ?., Weiss D., Yahalom J.(1999) Anodizing of Pure Magnesium in KOH-Aluminate Solutions under Sparkling. Journal of the Electrochemical Soceity, 146 (5), 1757–1761. DOI: 10.1149/1.1391838.
Review
For citations:
Chigrinova N.M., Vorobiova E.A., Chigrinov V.E. HOW TO MAKE MAGNESIUM ALLOYS BE RESISTANT TO OPERATIONAL RISKS. Science & Technique. 2016;15(5):435-441. (In Russ.) https://doi.org/10.21122/2227-1031-2016-15-5-435-441
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