Appearance of anodised aluminium: Effect of alloy composition and prior surface finish

Martin Aggerbeck, Stela Canulescu, Kai Dirscherl, Villads Egede Johansen, Sara Engberg, Jørgen Schou, Rajan Ambat

Research output: Contribution to journalJournal articleResearchpeer-review

16 Citations (Scopus)

Abstract

Effect of alloy composition and prior surface finish on the optical appearance of the anodised layer on aluminium alloys was investigated. Four commercial alloys namely AA1050, Peraluman 706, AA5754, and AA6082 were used for the investigation. Microstructure and surface morphology of the substrate prior to anodising were analysed using scanning electron microscopy and atomic force microscopy. The optical appearance of the anodised surface with and without sealing was investigated using a photography setup, photospectrometry and bidirectional reflectance distribution function. It was found that the roughness of the as-etched surface increases with the degree of alloying due to second phase particles making the reflection more diffused, and that the as-etched surface
morphology is similar to the oxide–substrate interface after anodising. Proper polishing is achieved on hard alloys and the glossy appearance was kept for alloys of high purity. Sealing made the specular reflection of the mechanically
polished specimens more distinct.
Original languageEnglish
JournalSurface and Coatings Technology
Volume254
Pages (from-to)28-41
Number of pages14
ISSN0257-8972
DOIs
Publication statusPublished - 15 Sep 2014
Externally publishedYes

Cite this