US4072797A
Expired / Lapsed
US
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Diffusion barrier and separation substance for metal parts adjoining each other in an oxygen free atmosphere
Assignee: CSEM Centre Suisse d'Electronique et de Microtechnique SA - Recherche et Développement
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Filing: 1975-08-04
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Granted: 1978-02-07
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Expires: 1995-08-04
Abstract
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° to 500° C.
Inventors
- 👤 Hans Gass
- 👤 Hans E. Hintermann
- 👤 Hartmut Griepentrog
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:44
CPC Classifications
C; C21; C21D; C21D1/00; C21D1/68; C21D1/70; Y; Y10; Y10S; Y10S60/00; Y10S60/909; Y10T; Y10T428/00; Y10T428/31
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
94 words
A diffusion barrier and separation substance for metal parts adjoining each other in an oxygen-free, inert, and preferably in a helium-containing atmosphere such as is used in a closed-cycle high-temperature reactor, comprising first and second metal parts with a hexagonally crystallized boron nitride forming a diffusion barrier and separation between said parts, wherein said hexagonally crystallized boron nitride is applied as a suspension to the adjoining metal parts, said metal parts being of a nickel-containing alloy and having smooth boundary surfaces therebetween, said parts being mounted for sliding relative movement in a thermoelastic suspension.
Claim 2
Dependent Claim
94 words
A diffusion barrier and separation substance for metal parts adjoining each other in an oxygen-free, inert, and preferably in a helium-containing atmosphere such as is used in a closed-cycle high-temperature reactor, comprising first and second metal parts with a hexagonally crystallized boron nitride forming a diffusion barrier and separation between said parts, wherein said hexagonally crystallized boron nitride is applied as a suspension to the adjoining metal parts, said metal parts being of a nickel-containing alloy and having smooth boundary surfaces therebetween, said parts being mounted for sliding relative movement in a thermoelastic suspension.
Claim 3
Dependent Claim
110 words
A diffusion barrier and separation substance for metal parts adjoining each other in an oxygen-free, inert, and preferably in a helium-containing atmosphere such as is used in a closed-cycle high-temperature reactor, comprising first and second metal parts with a hexagonally crystallized boron nitride forming a diffusion barrier and separation between said parts, said hexagonally crystallized boron nitride being applied to the boundary surface between the metal parts in an aqueous suspension prepared as a pasty liquid comprising from 5 to 50% of hexagonal boron nitride, 0.5 to 30% of binders, 2 to 6% of swelling agents, and 50 to 95% of a liquid suspending medium to form a protective film.
Claim 4
Dependent Claim
110 words
A diffusion barrier and separation substance for metal parts adjoining each other in an oxygen-free, inert, and preferably in a helium-containing atmosphere such as is used in a closed-cycle high-temperature reactor, comprising first and second metal parts with a hexagonally crystallized boron nitride forming a diffusion barrier and separation between said parts, said hexagonally crystallized boron nitride being applied to the boundary surface between the metal parts in an aqueous suspension prepared as a pasty liquid comprising from 5 to 50% of hexagonal boron nitride, 0.5 to 30% of binders, 2 to 6% of swelling agents, and 50 to 95% of a liquid suspending medium to form a protective film.
Claim 5
Dependent Claim
28 words
A diffusion barrier according to claim 2, wherein said protective film is burned in for 0.25 to 3 hours at a temperature of from 100° to 500° C.
Claim 6
Dependent Claim
20 words
A diffusion barrier according to claim 2, wherein said boron nitride is from 15 to 40% of the pasty liquid.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-06 | 1981-08-08 | 1982-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-06 | 1985-08-08 | 1986-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-06 | 1989-08-08 | 1990-02-07 | $7700.00 | Window Closed / Lapsed |