US3839779A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic brazing method
Assignee: United States Atomic Energy Commission
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Filing: 1973-09-07
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Granted: 1974-10-08
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Expires: 1993-09-07
Abstract
Abstract This invention is a method for brazing a ceramic body to a metal body wherein the bond between said bodies is resistant to high temperatures. A thin layer of a ceramic oxide powder is interposed between the surfaces of the ceramic and metal bodies which are to be joined. The two bodies with the powder therebetween are then subjected to a nonreducing atmosphere at a temperature of at least 1,650*C. for a minimum period of 5 minutes. These bodies are then cooled at a rate no greater than about 800*C. per hour, whereby an essentially hermetic ceramic oxide bond securely seals the two bodies together.
Inventors
- 👤 D Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:22
CPC Classifications
C; C04; C04B; C04B37/00; C04B37/02; C04B37/023; C04B37/025; B; B23; B23K; B23K35/00; B23K35/22; B23K35/24; B23K35/32; B23K35/327; H; H01; H01M; H01M50/00; H01M50/10; H01M50/183; H01M50/186; C04B2235/00; C04B2235/65; C04B2235/656; C04B2235/6565; C04B2237/00; C04B2237/02; C04B2237/04; C04B2237/06; C04B2237/064; C04B2237/30; C04B2237/32; C04B2237/34; C04B2237/343; C04B2237/345; C04B2237/348; C04B2237/40; C04B2237/403; C04B2237/50; C04B2237/76; H01M50/19; H01M50/191; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y10; Y10S; Y10S228/00; Y10S228/903
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
87 words
A METHOD OF BRAZING A CERAMIC BODY TO A METAL BODY COMPRISING INTERPOSING A THIN LAYER OF A CERAMIC OXIDE POWDER BETWEEN THE SURFACES OF SAID CERAMIC AND SAID METAL BODIES; HEATING SAID BODIES AND POWDER IN A NONREDUCING ATMOSPHERE TO AT LEAST 1,650*C, FOR A MINIMUM OF 5 MINUTES TO MELT SAID CERAMIC OXIDE POWDER, THEREBY BRAZING SAID BODIED TOGETHER; AND COOLING SAID BRAZED BODIES TO ROOM TEMPERATURE AT A RATE NO GREATER THAN 800*C. PER HOUR TO PREVENT THE CRACKING OF THE CERAMIC OXIDE BOND.
Claim 2
Independent Claim
87 words
A METHOD OF BRAZING A CERAMIC BODY TO A METAL BODY COMPRISING INTERPOSING A THIN LAYER OF A CERAMIC OXIDE POWDER BETWEEN THE SURFACES OF SAID CERAMIC AND SAID METAL BODIES; HEATING SAID BODIES AND POWDER IN A NONREDUCING ATMOSPHERE TO AT LEAST 1,650*C, FOR A MINIMUM OF 5 MINUTES TO MELT SAID CERAMIC OXIDE POWDER, THEREBY BRAZING SAID BODIED TOGETHER; AND COOLING SAID BRAZED BODIES TO ROOM TEMPERATURE AT A RATE NO GREATER THAN 800*C. PER HOUR TO PREVENT THE CRACKING OF THE CERAMIC OXIDE BOND.
Claim 3
Dependent Claim
42 words
The method according to claim 1 wherein said metal body is selected from the group consisting of molybdenum, niobium and niobium - 1 percent zirconium, and wherein said ceramic body is selected from the group consisting of alumina, yttria and calcium zirconate.
Claim 4
Dependent Claim
22 words
The method according to claim 1 wherein said ceramic oxide powder comprises lithium aluminate or lithium aluminate - 30 weight percent yttria.
Claim 5
Dependent Claim
22 words
The method according to claim 1 wherein said bodies are heated in a helium atmosphere to a temperature of about 1,650*-1, 725*C.
Claim 6
Independent Claim
115 words
A method of forming an electrical feedthrough for use in a high-temperature, secondary electrochemical cell, said feedthrough having a metal conducting rod passing through a ceramic body surrounded by a metal housing, comprising interposing a thin layer of a ceramic oxide powder between the contiguous surfaces of said ceramic body and said metal housing and rod; heating said feedthrough in a nonreducing atmosphere to at least 1,650*C. for a minimum of 5 minutes to melt said ceramic oxide powder, thereby brazing said ceramic body to said metal housing and rod; and cooling said feedthrough to room temperature at a rate no greater than 800*C. per hour to prevent the cracking of the ceramic oxide bond.
Claim 7
Independent Claim
115 words
A method of forming an electrical feedthrough for use in a high-temperature, secondary electrochemical cell, said feedthrough having a metal conducting rod passing through a ceramic body surrounded by a metal housing, comprising interposing a thin layer of a ceramic oxide powder between the contiguous surfaces of said ceramic body and said metal housing and rod; heating said feedthrough in a nonreducing atmosphere to at least 1,650*C. for a minimum of 5 minutes to melt said ceramic oxide powder, thereby brazing said ceramic body to said metal housing and rod; and cooling said feedthrough to room temperature at a rate no greater than 800*C. per hour to prevent the cracking of the ceramic oxide bond.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |