US3714702A
Expired / Lapsed
US
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Method for diffusion bonding refractory metals and alloys
Assignee: United States Atomic Energy Commission
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Filing: 1971-08-17
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Granted: 1973-02-06
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Expires: 1991-08-17
Abstract
Abstract An improvement in the method of diffusion-bonding articles comprised of refractory metals or alloy combinations thereof. The customary intermediate placed between the articles to promote bonding is modified by incorporating therein a dispersion of fine particles which at the bonding temperature are chemically and physically stable and substantially non-reactive and non-coherent with the intermediate. The dispersed particles are selected to be essentially mutually insoluble with the intermediate. The highenergy boundaries provided by the dispersed particles act as inexhaustible sinks for lattice vacancies in the matrix metal or alloy, thus suppressing the formation of Kirkendall voids in the interlayer between the articles.
Inventors
- 👤 J Hammond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:04
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/24; B23K35/32; B23K35/001; B23K35/005
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
133 words
In a diffusion-bonding process wherein an intermediate is interposed between faying surfaces of a refractory material selected from the group consisting of tungsten, tantalum, rhenium columbium, molybdenum, and alloy combinations thereof and wherein the resulting assembly is maintained at an elevated temperature and under pressure in a non-oxidizing atmosphere to effect coalescence of said intermediate and said surfaces, said intermediate being more deformable than said surfaces and consisting at least in part of a metallic component which at said temperature diffuses into said material at a faster rate than said material diffuses into said component, the improvement comprising incorporating in said component a dispersion of ultrafine particles which at said temperature are chemically and physically stable and substantially non-reactive and non-coherent with said component, said particles and said component being essentially mutually insoluble.
Claim 2
Dependent Claim
133 words
In a diffusion-bonding process wherein an intermediate is interposed between faying surfaces of a refractory material selected from the group consisting of tungsten, tantalum, rhenium columbium, molybdenum, and alloy combinations thereof and wherein the resulting assembly is maintained at an elevated temperature and under pressure in a non-oxidizing atmosphere to effect coalescence of said intermediate and said surfaces, said intermediate being more deformable than said surfaces and consisting at least in part of a metallic component which at said temperature diffuses into said material at a faster rate than said material diffuses into said component, the improvement comprising incorporating in said component a dispersion of ultrafine particles which at said temperature are chemically and physically stable and substantially non-reactive and non-coherent with said component, said particles and said component being essentially mutually insoluble.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein said dispersion is incorporated in said component prior to interposition of said intermediate between said surfaces.
Claim 4
Dependent Claim
36 words
The process of claim 1 wherein said dispersion is formed in situ in said component in the course of the diffusion bonding operation by a heat-initiated chemical reaction between said component and a material dispersed therein.
Claim 5
Dependent Claim
25 words
The method of claim 1 wherein said dispersion consists of particles having an average diameter in the range of about 0.05 micron to 1.0 micron.
Claim 6
Dependent Claim
25 words
The method of claim 4 wherein said dispersion consists of particles having an average interparticle spacing in the range of about 0.2 to 2.0 microns.
Claim 7
Dependent Claim
28 words
The method of claim 1 wherein said component is a metallic material selected from the group consisting of tantalum, rhenium, molybdenum, zirconium, and vanadium, and alloy combinations thereof.
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) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |