Cleaning aluminum workpieces

US5997721A · kind A · utility

Assignee

• Alcan International Limited · CA

Inventors

• Peter K. F. Limbach · Oettingen, DE
• Armin Kumpart · Bodenfelde, DE
• Nigel C. Davies · Huntsville, CA
• Jonathan Ball · Alcester, GB

Key dates

• Filing date: Oct 16, 1997
• Grant date: Dec 7, 1999
• Expiry date: Oct 16, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C25D5/44
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A method of cleaning an Al workpiece comprises a.c. anodising the workpiece in an acidic electrolyte capable of dissolving aluminium oxide and maintained at a temperature of at least 70.degree. C. under conditions such that the surface of the workpiece is cleaned with any oxide film thereon being non-porous and no more than about 20 nm thick.