Process for manufacture of silver-based composite powders for electrical contact materials and composite powders so produced

US7566437B2 · kind B2 · utility

Assignee

• UMICORE AG & CO. KG · DE

Inventors

• Dan V. Goia · Potsdam, US
• Bernd Kempf · Alzenau, DE
• Inge Fallheier · Gelnhausen, DE
• Roger Wolmer · Gelnhausen, DE
• Andreas Koffler · Meißen, DE

Key dates

• Filing date: Mar 31, 2006
• Grant date: Jul 28, 2009
• Expiry date: Aug 29, 2026

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B22F2998/10
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The present invention relates to a method for manufacture of silver-based composite powders for electrical contact materials. The invention relates also to electrical contact materials made from such composite powders. The process comprises a high energy dispersing process of wet silver oxide (Ag2O) with additional second oxide components in aqueous suspension. The high energy dispersing process can be conducted by high shear mixing or by high energy milling. Preferably high speed dispersing units working at rotating speeds in the range of 5,000 to 30,000 rpm or high energy mills such as attritor mills are used. The new process is versatile, economical and offers access to a broad spectrum of contact materials. The silver-based composite powders made according to the new process yield contact materials with a highly dispersed microstructures and superior material characteristics.