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ArticleName Adhesive conversion lacquer coatings on magnesium alloys
DOI 10.17580/tsm.2019.10.11
ArticleAuthor Abrashov A. A., Grigoryan N. S., Simonova M. A., Asnis N. A.

D. Mendeleev University of Chemical Technology of Russia, Chair of Innovation Materials and Corrosion Protection, Moscow, Russia:

A. A. Abrashov, Associate Professor, Candidate of Engineering Sciences, e-mail:
N. S. Grigoryan, Associate Professor, Candidate of Сhemical Sciences, e-mail:
M. A. Simonova, Student, e-mail:
N. A. Asnis, Leading Engineer, Candidate of Engineering Sciences, e-mail:


Magnesium alloys come short of corrosion resistance due to high negative values of their standard potentials. Lacquer coating is one of the most poplar methods to prevent corrosion of magnesium alloy products. As adhesion layers under lacquer coating before coloring of magnesium and its alloys, chromate coatings are widely applied. The major drawback of chromatizing solutions is their high toxicity resulting from hexavalent chromium compound involved. In recent years, as an alternative to chromate layers on magnesium and its allows, nanosize conversion titanium- and (or) zirconium-containing adhesive coatings made of solutions of hexafluoro zirconic and hexafluoro titanic acids are widely used in international practice. The solution composed of hexafluoro zirconic (H2ZrF6), hexafluoro titanic (H2TiF6) and tartaric (C4H6O6) acids is developed. The corrosion tests show that protective properties of new coatings meet the requirements imposed on adhesive layers to underlay lacquer coatings: the invasion depth of corrosion from the notch groove is within 2 mm after 100 h of curing in the salt-spray chamber. It is found that lacquer coating with the developed adhesive underlayer posesses higher adhesion strength as compared with chromate coatings.

keywords Titanium- and zirconium-containing coatings, corrosion protection, magnesium surface treatment, adhesive coatings, conversion coatings

1. Fuyong Cao, Guang-Ling Song, Andrej Atrens. Corrosion and passivation of magnesium alloys. Corrosion Science. 2016. Vol. 111. pp. 835–845.
2. Castano C. E., Maddela S., O’Keefe M. J., Wang Y. M. A comparative study on the corrosion resistance of cerium-based conversion coatings on AZ91D and AZ31B magnesium alloys. ECS Transactions. 2012. Vol. 41, No. 15. pp. 3–12.
3. Fusheng Pan, Xu Yang, Dengfei Zhang. Chemical nature of phytic acid conversion coating on AZ61 magnesium alloy. Applied Surface Science. 2009. Vol. 255. pp. 8363–8371.
4. Chen X. B., Birbilis N., Abbott T. B. Review of corrosion-resistant conversion coatings for magnesium and its alloys. Corrosion. 2011. Vol. 67, No. 3. pp. 035005-1-035005-16.
5. Aihua Yi, Jun Du, Jian Wang et al. Preparation and characterization of colored Ti/Zr conversion coating on AZ91D magnesium alloy. Surface and Coatings Technology. 2015. Vol. 276. pp. 239–247.
6. Gulbrandsen E., Taftø J., Olsen A. The passive behaviour of Mg in alkaline fluoride solutions. Electrochemical and electron microscopical investigations. Corrosion Science. 1993. Vol. 34, No. 9. pp. 1423–1440.
7. Verdier S., van der Laak N., Delalande S. et al. The surface reactivity of a magnesium–aluminium alloy in acidic fluoride solutions studied by electrochemical techniques and XPS. Applied Surface Science. 2004. Vol. 235, No. 4. pp. 513–524.
8. Chiu K. Y., Wong M. H., Cheng F. T., Man H. C. Characterization and corrosion studies of fluoride conversion coating on degradable Mg implants. Surface and Coatings Technology. 2007. Vol. 202, No 3. pp. 590–598.
9. Pat. US 7402214 USA. Conversion Coatings Including Alkaline Earth Metal Fluoride Complexes. Applied : 28.04.03. Published : 22.07.08.
10. Pat. US 7175882 USA. Process for Coating Metal Surfaces. Applied : 01.10.01. Published : 13.02.07.
11. Woicik J. C. Hard X-Ray Photoelectron Spectroscopy (HAXPES). Springer International Publishing Switzerland, 2016. 571 p.
12. Laha P., Schram T., Terry H. Use of spectroscopic ellipsometry to study Zr/Ti films on Al. Surface Interface Analysis. 2002. Vol. 34, No. 1. pp. 677–680.

13. ASTM D4541–17. Standard Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers.
14. State Standard GOST 9.401–91. Unified corrosion and ageing protection system. Lacquer coatings. General requirements and accelerated weathering testing methods. Effective as of 01.07.2019.
15. ASTM B117–11. Standard Practice for Operating Salt Spray (Fog) Apparatus.
16. Abrashov A. A., Grigoryan N. S., Volkova A. E. et al. Protective titaniumcontaining nanocoatings on galvanized steel. Galvanotekhnika i obrabotka poverkhnosti. 2016. Vol. 24, No. 2. pp. 28–34.
17. Abrashov A. A., Grigoryan N. S., Vagramyan T. A., Zhilenko D. Yu. Titaniferous protective coatings on aluminum alloys. Non-Ferrous Metals. 2016. No. 1. pp. 33–37.

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