Diffusion barrier and separation substance for metal parts adjoining each other in an oxygen free atmosphere

US4072797A · kind A · utility

Assignees

• Laboratoire Suisse de Recherches Horlogeres · CH
• Gutehoffnungshutte Sterkrade Aktiengesellschaft

Inventors

• Hans Gass
• Hans E. Hintermann · Riedlingen, DE
• Hartmut Griepentrog · Oberhausen, DE

Key dates

• Filing date: Aug 4, 1975
• Grant date: Feb 7, 1978
• Expiry date: Aug 4, 1995

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/31
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A diffusion barrier and separation substance for metal parts which adjoin each other in an oxygen-free, inert and preferably a helium-containing atmosphere such as used in a closed-cycle high temperature reactor or gas turbine comprises first and second adjoining metal parts with a hexagonal boron nitride placed between said parts. The hexagonal boron nitride is applied to the boundary surface of the metal parts in an aqueous or organic suspension prepared as a pasty, putty-like or brushable liquid substance. The substance contains from 5 to 50% of boron nitride, from 0.5 to 30% of binders and from 2 to 6% of swelling agents and 50 to 90% liquid suspension medium. The suspension medium may advantageously contain an anti-corrosive agent and in addition the formed protective film is burned from 0.25 to 3 hours at a temperature of from 100.degree. to 500.degree. C.