Method for producing composite powders based on silver-tin oxide, the composite powders so produced, and the use of such powders to produce electrical contact materials by powder metallurgy techniques

US6409794B1 · kind B1 · utility

Assignee

• DMC, INC · DE

Inventors

• Roger Wolmer · Gelnhausen, DE
• Mechthild Mueller · Hasselroth, DE
• Frank Heringhaus · Alzenau, DE
• Dietrich Ruehlicke · Leutershausen, DE
• Dan V. Goia · Potsdam, US

Key dates

• Filing date: Apr 4, 2001
• Grant date: Jun 25, 2002
• Expiry date: Apr 4, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01H1/02376
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A method for producing composite powders based on silver-tin oxide, by chemically reductive precipitation of silver onto particulate tin oxide. A solution of a silver compound and a solution of a reducing agent are simultaneously added in stoichiometrically equivalent amounts, separately and continuously with intensive mixing, to an aqueous suspension of tin oxide. The resulting composite powders have very high homogeneity, and can be processed to make electrical contact materials. The method is particularly suitable for producing composite powders based on silver-tin oxide doped with indium oxide, to be used in the manufacture of electrical contact materials.