US4230745A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of encapsulating a molded ceramic member
Assignee: MTU Aero Engines AG
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Filing: 1978-08-03
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Granted: 1980-10-28
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Expires: 1998-08-03
Abstract
Abstract For the encapsulation of a molded ceramic member for high-temperature isostatic pressing, the molded member, which preferably is of silicon ceramic, is covered with a dense surface coating of an Si melt. Thereafter, the coating is exposed to an N 2 atmosphere at a temperature of within about 800° to 1400° C. for so long until the Si coating is converted into a Si 3 N 4 coating.
Inventors
- 👤 Wolfgang Betz
- 👤 Axel Rossmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:50
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; B; B22; B22F; B22F3/00; B22F3/12; B22F3/1208; B22F3/1258; B22F3/1266; B22F3/14; B22F3/15; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/593; C04B35/622; C04B35/64; C04B35/645; C04B35/6455; C04B41/45; C04B41/50; C04B41/5053; C04B41/5062; C04B41/5066; C04B41/80; C04B41/81; C04B41/85; C04B41/87
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
68 words
In a method for encapsulating a molded member of ceramic, such as silicon ceramic for high-temperature isostatic pressing; the improvement comprising coating said molded member with a dense surface coating of Si melt; and thereafter exposing said coating to an N.sub. 2 atmosphere at a temperature in the range of about 800° C. to 1400° C. until the Si coating is converted into a Si.sub. 3N.sub. 4 coating.
Claim 2
Dependent Claim
68 words
In a method for encapsulating a molded member of ceramic, such as silicon ceramic for high-temperature isostatic pressing; the improvement comprising coating said molded member with a dense surface coating of Si melt; and thereafter exposing said coating to an N.sub. 2 atmosphere at a temperature in the range of about 800° C. to 1400° C. until the Si coating is converted into a Si.sub. 3N.sub. 4 coating.
Claim 3
Dependent Claim
20 words
Method as claimed in claim 1, comprising evacuating said molded member prior to the coating thereof with said Si melt.
Claim 4
Dependent Claim
44 words
Method as claimed in claim 1, comprising filling said molded member with N.sub. 2 prior to coating thereof with said Si melt; and infiltrating the Si melt into the pore structure of the molded member under a low positive pressure of about 1 bar.
Claim 5
Dependent Claim
28 words
Method as claimed in any one of the preceding claims, comprising adding about 1% to 10% Mg0 to the Si melt so as to improve the viscosity 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) | 1983-10-28 | 1984-04-28 | 1984-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-28 | 1988-04-28 | 1988-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-28 | 1992-04-28 | 1992-10-28 | $7700.00 | Window Closed / Lapsed |