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COMPOSITES AND MULTIPURPOSE COATINGS
ArticleName Analyzing the effect of iron and silicon impurities in 5005A alloy on the appearance of anodic sheet coatings
DOI 10.17580/tsm.2023.10.08
ArticleAuthor Ivanova A. O., Ryabov D. K., Gradoboev A. Yu., Malakhova Yu. V.
ArticleAuthorData

Institute of Light Materials and Technologies Ltd., Moscow, Russia
A. O. Ivanova, Project Leader, e-mail: Anna.Ivanova4@rusal.com
D. K. Ryabov, Chief Scientific Officer
A. Yu. Gradoboev, Department Director
Yu. V. Malakhova, Specialist

Abstract

Aluminium is widely used in construction for exterior and interior decoration. For this, panels made of anodized alloy sheets, mainly of the Al – Mg system, are used. However, the chemical composition of an alloy grade may vary from batch to batch. This may lead to colour variation in construction elements, as well as to additional costs associated with the need to replace panels that stand out against the general background. This paper describes a study that looked at how the composition of the alloy 5005A influences the appearance of the anodic coatings of sheets in the H24 as-supplied state. It is shown that an increase in iron and silicon content affects the glitter of anodic coatings. Another effect includes a darkened colour of anodized sheets. The probable cause is an increase in the surface roughness after etching and anodizing and the presence of ferrous phases in the nearsurface layers and in the coating, which refract the impinging light. A negative effect of iron and silicon impurities on the specular gloss of uncoated sheets was noted during visual assessment. The decreased reflectivity of the sheets correlates well with the data on the decreased glitter of anodic coatings.

keywords Aluminium alloy, anodizing, sheets of 5005А alloy, glitter of anodic coatings, iron and silicon impurities
References

1. Anisimov S. A., Abakumov R. G. A comparative analysis of composite aluminium panel facades used in construction. Innovatsionnaya nauka. 2017. Vol. 3, No. 4. pp. 11–13.
2. Zhukov A. D. Ventilated façade systems. Nauka, stroitelstvo, obrazovanie. 2012. No. 1. p. 3.
3. Makarova A. A., Saporovskaya T. Yu. Analysis of modern panel facades made of various materials. Days of Student Science of the Institute of Architecture, Civil Engineering and Energy-2020: Conference proceedings. 2020. pp. 68–75.
4. Fedosov S. V., Rumyantseva V. E., Fedosova N. L., Rumyantseva K. E. Anticorrosion protection of metals in construction: Problems and possible solutions. Stroitelstvo i rekonstruktsiya. 2021. No. 2. pp. 97–103.
5. Averianov E. E. Handbook of anodizing. Moscow : Mashinostroenie, 1988. 132 p.
6. Timm J. Influence of Fe and Si containing phases on the anodisation behaviour. Key Engineering Materials. 1990. Vol. 44-45. pp. 219–232. DOI: 10.4028/www.scientific.net/KEM.44-45.219
7. Van Gils S., Dimogerontakis T., Buytaert G., Stijns E. et al. Optical properties of magnetron-sputtered and rolled aluminum. Journal of Applied Physics. 2005. Vol. 98. 083505. DOI: 10.1063/1.2085315
8. Buytaert G., Terryn H., Van Gils S., Kernig B. et al. Study of the nearsurface of hot- and cold-rolled AlMg0.5 aluminium alloy. Surface and Interface Analysis. 2005. No. 37. pp. 534–543. DOI: 10.1002/SIA.2046
9. Premendra J., Chen J. H., Tichelaar F. D., Terryn H. et al. Optical and transmission electron microscopical study of the evolution of surface layer on recycled aluminium along the rolling mills. Surface & Coatings Technology. 2007. Vol. 201. pp. 4561–4570. DOI: 10.1016/J.SURFCOAT.2006.09.090
10. Ratchev P., Labie R., Verlinden B., Van Den Broeck R. About the reasons of streaks appearance on the surface of etched plates of commercial purity AA1080 aluminium. Zeitschrift Fur Metallkunde. 2000. Vol. 91. pp. 510–515.
11. Buytaert G., Terryn H., Van Gils S., Kernig B. et al. Investigation of the (sub)surface of commercially pure rolled aluminium alloys by means of total reflectance, r.f. GDOES, SEM/EDX and FIB/TEM analysis. Surface and Interface Analysis. 2006. Vol. 38. pp. 272–276. DOI: 10.1002/SIA.2205
12. Karhausen K. F., Dons A. L., Aukrust T. Microstructure control during extrusion with respect to surface quality. Materials Science Forum. 1996. Vol. 217-222. pp. 403–408. DOI: 10.4028/www.scientific.net/MSF.217-222.403
13. Zhu H., Zhang X., Couper M. J., Dahle A. K. Effect of initial microstructure on surface appearance of anodized aluminum extrusions. Metallurgical and Materials Transactions A. 2009. Vol. 40, Iss. 13. pp. 3264–3275. DOI: 10.1007/s11661-009-9976-0
14. Vander Voort G., Suárez Peña B., Asensio Lozano J. Microstructure investigations of streak formation in 6063 aluminum extrusions by optical metallographic techniques. Microscopy and Microanalysis. 2013. Vol. 19. pp. 276–284. DOI: 10.1017/S143192761300010X
15. Zhu H., Wei T., Couper M. J., Dahle A. K. Effect of Fe-rich particles on the formation of die streaks on anodized aluminum extrusions. The Journal of the Minerals, Metals and Materials Society. 2012. Vol. 64. pp. 337–345. DOI: 10.1007/s11837-012-0252-1
16. Saito M. Unoxidized aluminum particles in anodic alumina films. Journal of the Electrochemical Society. 1993. Vol. 140. 1907. DOI: 10.1149/1.2220737
17. Saito M., Shiga Y., Miyagi M., Wada K. et al. Optical transmittance of anodically oxidized aluminum alloy. Japanese Journal of Applied Physics. 1995. Vol. 34. pp. 3134–3138. DOI: 10.1143/JJAP.34.3134
18. Ma Y., Zhou X., Thompson G. E., Nilsson J. O. et al. Anodizing of
AA6063 aluminium alloy profiles: generation of dark appearance. Surface and Interface Analysis. 2013. Vol. 45. pp. 1479–1484. DOI: 10.1002/sia.5219
19. Hultquist A. E. On the nature of burned anodic coatings. Journal of the Electrochemical Society. 1964. Vol. 111. 1302. DOI: 10.1149/1.2425989
20. Chang R., Hall W. F. On the correlation between optical properties and the chemical /metallurgical constitution of multi-phase thin films. Thin Solid Films. 1977. Vol. 46. pp. 5–8. DOI: 10.1016/0040-6090(77)90068-2
21. Sheasby P. G., Pinner R. The surface treatment and finishing of aluminium and its alloys. Vol. 2. 6th edition. ASM International, 2001. 350 p.
22. Veys-Renaux D., Chahboun N., Rocca E. Anodizing of multiphase aluminium alloys in sulfuric acid: in-situ electrochemical behaviour and oxide properties. Electrochimica Acta. 2016. Vol. 211. pp. 1056–1065. DOI: 10.1016/j.electacta.2016.06.131
23. GOST 1497–84. Metals. Methods of tension test. Introduced: 01.01.1986.
24. GOST 9.305–84. Unified system of corrosion and ageing protection. Metal and non-metal inorganic coatings. Technological process operations for coating production. Introduced: 01.01.1986.
25. ISO 7668:2010 EN. Anodizing of aluminium and its alloys – measurement of specular reflectance and specular gloss of anodic oxidation coatings at angles of 20 degrees, 45 degrees, 60 degrees or 85 degrees. Published: 01.11.2010.
26. GOST 9.031–74. Unified system of corrosion and ageing protection. Anode-oxide coatings for semifinished products made of aluminium and its alloys. General requirements and methods of control. Introduced: 01.07.1975.
27. DIN EN 485-2–2018. Aluminium and aluminium alloys. Sheet, strip and plate. Part 2: Mechanical properties. Published: 01.12.2018.

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