Effect of Alloying Elements on the Colour Development of Anodised Al-Mg-Si Alloys


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Colour of the anodised Al-Mg-Si alloys was quantified by spectrophotometric method defining L* (lightness), a* (greenness-redness) and b* (blueness- yellowness) values. All alloys exhibited yellow and green colour. The yellowness of the anodised surfaces increased significantly with the increase of Cu while increasing Mn reduced the greenness. Effect of trace elements V and Ni was negligible while Zn caused slightly yellowness. Fe reduced the lightness of the surfaces, while its effect on colour was insignificant. Smut layer being formed during alkaline etching (prior to anodising) was desmutted/deoxidised in different acid solutions, some of which failed to clean the etched surfaces. Remaining smut however caused minor effect on colour.



Materials Science Forum (Volumes 794-796)

Edited by:

Knut Marthinsen, Bjørn Holmedal and Yanjun Li




E. Senel and M. Hallenstvet, "Effect of Alloying Elements on the Colour Development of Anodised Al-Mg-Si Alloys", Materials Science Forum, Vols. 794-796, pp. 247-252, 2014

Online since:

June 2014




* - Corresponding Author

[1] P. Sheasby and R. Pinner, The Surface Treatment and Finishing of Aluminium and its Alloys. ASM International, Metals Park, Ohio, (2001).

[2] A.W. Brace, E. Strazzi, and W.D. Barba, Alusurface 94: A seminar for Professional Up-dating in Surface Finishing of Aluminium, Interall Publications, Amsterdam, Holland, (1994).

[3] T. Furu, N. Telioui, C. Behrens, J. Hasenclever, P. Schaffer, Proceedings of the 12th Internation Conference on Aluminium Alloys, 2010, Yokohama, Japan (2010).

[4] B. Holme, N. Ljones, A. Bakken, O. Lunder, J. E. Lein, L. Vines, T. Hauge, Ø. Bauger and K. Nisancioglu, Preferential grain etching of AlMgSi(Zn) model alloys. J. Electroch. Soc. 157, (2010) C424-C427.

DOI: https://doi.org/10.1149/1.3422584

[5] Ø. Bauger, H. Bjerkaas, Aspects of Preferential Grain Etching During Alkaline Pre-Etching Step Before Anodizing of Aluminum Profiles, Proceeding paper, 10th International Extrusion Technology Seminar, May 15-18, 2012, Miami.

[6] O. Lunder, Ø. Bauger, J.C. Walmsley, J.E. Lein, Effect of trace element nickel on corrosion behaviour of aa6060 aluminium in chloride solution, Proceeding paper, VI. Aluminium Surface Science and Technology Seminar, May 27-31, 2012, Sorrento.