Method of producing oxide ceramic layers on barrier layer-forming metals and articles produced by the method

US5385662A · kind A · utility

Assignee

• Electro Chemical Engineering GmbH · CH

Inventors

• Peter Kurze · Pulsnitz, DE
• Dora Banerjee · Kerpen, DE
• Hans-Jurgen Kletke · Luckau, DE

Key dates

• Filing date: Nov 25, 1992
• Grant date: Jan 31, 1995
• Expiry date: Nov 25, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C25D11/30
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A method of producing oxide ceramic layers on Al, Mg, Ti, Ta, Zr, Nb, Hf, Sb, W, Mo, V, Bi or their alloys by a plasma-chemical anodical oxidation in a chloride-free electrolytic bath having a pH value of 2 to 8 and a constant bath temperature of -30.degree. to +15.degree. C. A current density of at least 1 A/dm.sup.2 is maintained constant in the electrolytic bath until the voltage reaches a predetermined end value.