A CONTRIBUTION TO THE UNDERSTANDING OF AC ANODIZING OF ALUMINUM

• Type: Article in International Scientific Journal
• Date: 1989

Authors

Mário Adolfo Barbosa (Author) FEUP; GABE, DR (Author) Other; ROSS, DH (Author) Other; SUTHERLAND, I (Author) Other

Journal

Title: Journal of Applied Electrochemistry

Vol. 19

Pages: 829-838

ISSN: 0021-891X

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 5 Citations

Scopus - 4 Citations

Other information

Authenticus ID: P-001-SBW

DOI: 10.1007/bf01007930

Abstract (EN): Commercial aluminium has been anodized in 10% v/v sulphuric acid using alternating current. At 20 V no significant differences in colour and thickness between specimens anodized at the neutral and live terminals were detected. At higher voltages the oxide on the neutral specimens was always more yellow and thinner than that on the live specimens. The colouration was attributed to the reduction of sulphate to sulphide during the cathodic half-cycle, no other sulphur-containing species being detected by XPS. EPMA has shown that the total sulphur distribution across the film was practically uniform and independent of the operating conditions, except in thin films, where it was greatest at the free surface. With additions of ferric sulphate to the solution the reduction to sulphide was inhibited and the differences between live and neutral specimens were avoided. The total amount of sulphur remained unchanged at approximately 5% weight and no iron was incorporated in the film. © 1989 Chapman and Hall Ltd.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10