Journal ArticleDOI
Structural Features of Oxide Coatings on Aluminum
TLDR
In this paper, the structural features of the porous type of anodic oxide coating applied to aluminum have been investigated with the electron microscope, and formulas were given for calculating the cell size and pore volume of these coatings.Abstract:
The structural features of the porous type of anodic oxide coating applied to aluminum have been investigated with the electron microscope. These coatings consist of close‐packed cells of oxide, predominately hexagonal in shape, each of which contains a single pore. Pore size is a function of the electrolyte used and is independent of forming voltage. Wall thickness and barrier thickness are primarily a function of forming voltage and are affected to a minor degree by the electrolyte type. Pertinent dimensions of anodic coatings formed in sulfuric acid, oxalic acid, chromic acid, and phosphoric acid electrolytes are presented, and formulas are given for calculating the cell size and pore volume of these coatings.read more
Citations
More filters
Journal ArticleDOI
Investigation of the porosity of thin Anodic Al2O3 films by interference of photoluminescence radiation
TL;DR: In this article, the porosity coefficients of thin Al 2 O 3 films formed by d.c. anodization of pure aluminium in 0.1 M oxalic acid have been investigated under the conditions of Lummer-Gehrke-type interference.
Journal ArticleDOI
Conditions for transition from barrier to porous oxidation of aluminum in phosphoric acid solutions
TL;DR: In this article, anodic oxidation of aluminum foil specimens in the phosphoric acid solutions of various concentrations was studied under the galvanostatic conditions at various current densities, and it was shown that the critical oxidation efficiency for the transition from barrier oxidation to porous oxidation is equal to the reciprocal of the Pilling-Bedworth ratio (0.61).
Journal ArticleDOI
Manufacturing of highly ordered porous anodic alumina with conical pore shape and tunable interpore distance in the range of 550 nm to 650 nm
Małgorzata Norek,Maksym Łażewski +1 more
TL;DR: In this paper, highly ordered porous anodic alumina (PAA) with tapered pore structure and interpore distance (Dc) in the range of 550 nm to 650 nm were fabricated.
Book ChapterDOI
Anodic Oxide Films on Aluminum: Their Significance for Corrosion Protection and Micro- and Nano-Technologies
TL;DR: The reason why aluminum metal only became available fairly recently is that aluminum has a strong chemical affinity to oxygen, and this prevents reduction of aluminum oxide by chemical reaction with carbon at high temperatures, unlike iron- and copper-oxides as discussed by the authors.
Journal ArticleDOI
The influence of certain sulfonic triphenylmethane dyes, as additives, on anodizing of aluminum in phosphoric acid
TL;DR: In this article, the anions of the triphenylmethane sulfonic dye Light Green and its isomer Brilliant Blue added in the bath during anodization of pure aluminum (99.96%) in 0.4 M phosphoric acid under constant voltage, are concentrated at the bottom of the pores of the anodic coating and influence the anode process.
Related Papers (5)
Ordered Metal Nanohole Arrays Made by a Two-Step Replication of Honeycomb Structures of Anodic Alumina
Hideki Masuda,Kenji Fukuda +1 more
The morphology and mechanism of formation of porous anodic films on aluminium
J. P. O'Sullivan,G. C. Wood +1 more