US4011076A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for fabricating beryllium structures
Assignee: Energy Research and Development Administration ERDA
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Filing: 1976-03-18
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Granted: 1977-03-08
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Expires: 1996-03-18
Abstract
Abstract Thin-walled beryllium structures are prepared by plasma spraying a mixture of beryllium powder and about 2500 to 4000 ppm silicon powder onto a suitable substrate, removing the plasma-sprayed body from the substrate and placing it in a sizing die having a coefficient of thermal expansion similar to that of the beryllium, exposing the plasma-sprayed body to a moist atmosphere, outgassing the plasma-sprayed body, and then sintering the plasma-sprayed body in an inert atmosphere to form a dense, low-porosity beryllium structure of the desired thin-wall configuration. The addition of the silicon and the exposure of the plasma-sprayed body to the moist atmosphere greatly facilitate the preparation of the beryllium structure while minimizing the heretofore deleterious problems due to grain growth and grain orientation.
Inventors
- 👤 Victor M. Hovis, Jr.
- 👤 Walter G. Northcutt, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:21
CPC Classifications
C; C23; C23C; C23C4/00; C23C4/04; C23C4/06; B; B22; B22F; B22F3/00; B22F3/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
108 words
A method for fabricating a thin-walled beryllium structure, comprising the steps of preparing a mixture of beryllium powder and elemental silicon powder with a concentration of silicon in a range of about 2500 to 4000 ppm, plasma spraying the mixture onto a substrate, removing the sprayed body from the substrate, exposing the plasma-sprayed body to a moist atmosphere for a duration sufficient to effect absorption of liquid water therein, confining the sprayed body within a sizing die having coefficient of thermal expansion substantially similar to that of beryllium, out-gassing the plasmasprayed body in vacuum at an elevated temperature, and thereafter sintering the plasma-sprayed body in an inert atmosphere.
Claim 2
Independent Claim
108 words
A method for fabricating a thin-walled beryllium structure, comprising the steps of preparing a mixture of beryllium powder and elemental silicon powder with a concentration of silicon in a range of about 2500 to 4000 ppm, plasma spraying the mixture onto a substrate, removing the sprayed body from the substrate, exposing the plasma-sprayed body to a moist atmosphere for a duration sufficient to effect absorption of liquid water therein, confining the sprayed body within a sizing die having coefficient of thermal expansion substantially similar to that of beryllium, out-gassing the plasmasprayed body in vacuum at an elevated temperature, and thereafter sintering the plasma-sprayed body in an inert atmosphere.
Claim 3
Dependent Claim
39 words
The method claimed in claim 1, wherein the beryllium powder has a particle size in the range of 35 to 53 microns, and wherein the silicon powder has a particle size in the range of 4 to 30 microns.
Claim 4
Dependent Claim
47 words
The method claimed in claim 1, wherein the step of exposing the plasma-sprayed body to the moist atmosphere is achieved by exposing the plasma-sprayed body to an air atmosphere having a relative humidity level of at least 30 percent for a duration of at least 1 hour.
Claim 5
Dependent Claim
79 words
The method claimed in claim 3, wherein the out-gassing step is achieved by heating the die-confined plasma sprayed body to a temperature in the range of 700°-800° C. under a vacuum at a pressure in the range of 1 × 10.sup. -6 to 1 × 10.sup. -7 torr, and wherein sintering step is achieved in an inert atmosphere at a pressure in the range of 1 to 5 psia and at a temperature in the range of 1100°-1200° C.
Claim 6
Dependent Claim
33 words
The method claimed in claim 4, wherein the steps of outgassing and sintering occur in a vacuum furnace without exposing the out-gassed plasma-sprayed body to an oxidizing atmosphere prior to the sintering step.
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) | 1980-03-07 | 1980-09-06 | 1981-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-07 | 1984-09-06 | 1985-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-07 | 1988-09-06 | 1989-03-08 | $7700.00 | Window Closed / Lapsed |