Active brazing solder for brazing alumina-ceramic parts

US6770377B2 · kind B2 · utility

Assignee

• Endress+Hauser Inc. · DE

Inventors

• Frank Hegner · Bad Kötzting, DE
• Elke Schmidt · Bad Säckingen, DE
• Volker Guther · Altdorf, DE
• Anobecs Allo · Fürth, DE
• Jurgen Breme · Heusweiler, DE
• Heinz Muller · Erlangen, DE
• Jürgen Peter Turnsek · Völklingen, DE

Key dates

• Filing date: Jun 12, 2002
• Grant date: Aug 3, 2004
• Expiry date: Jan 12, 2023

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C04B2237/343
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The active brazing solder for brazing ceramic parts of alumina, particularly of high-purity alumina, contains a maximum of 12 wt. % Ti, a maximum of 8 wt. % Be, and less than 16.5 wt. % Fe, the remainder being Zr and any impurities that may be present. The active brazing solder has the following behaviour/features: Brazing temperature: lower than 1,000° C.; the brazed joint is high-vacuum-tight over a long period of time; the coefficient of thermal expansion of the active brazing alloy is substantially identical to that of the alumina ceramic in the entire temperature range covered during the brazing process; the strength of the brazed joint between the two ceramic parts is so high that under tensile loading, fracture will result not at the joint, but in the adjacent ceramic; the pressure resistance of the active brazing solder is greater than 2 GPa; the active brazing solder is very good processable into powders having particle sizes on the order of 10 &mgr;m.