Patent US4598024A successfully refreshed from Google Patents.
US4598024A
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US
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Dispersion toughened ceramic composites and method for making same
Assignee: Lockheed Martin Energy Systems Inc
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Filing: 1984-09-28
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Granted: 1986-07-01
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Expires: 2004-09-28
Abstract
Abstract Ceramic composites exhibiting increased fracture toughness are produced by the simultaneous codeposition of silicon carbide and titanium disilicide by chemical vapor deposition. A mixture of hydrogen, methyltrichlorosilane and titanium tetrachloride is introduced into a furnace containing a substrate such as graphite or silicon carbide. The thermal decomposition of the methyltrichlorosilane provides a silicon carbide matrix phase and the decomposition of the titanium tetrachloride provides a uniformly dispersed second phase of the intermetallic titanium disilicide within the matrix phase. The fracture toughness of the ceramic composite is in the range of about 6.5 to 7.0 MPa√m which represents a significant increase over that of silicon carbide.
Inventors
- 👤 David P. Stinton
- 👤 Walter J. Lackey
- 👤 Robert J. Lauf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:13
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/50; C04B41/5053; C04B41/5062; C04B41/5071; C04B41/80; C04B41/81; C04B41/85; C04B41/87; C23; C23C; C23C16/00; C23C16/22; C23C16/30
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
48 words
A ceramic structure comprising a ceramic substrate capable of withstanding a temperature of at least about 1,200° C. and -1,500° C. and a ceramic composite coating thereon, said coating comprising a matrix phase of silicon carbide and an intermetallic phase of titanium disilicide uniformly dispersed within said matrix.
Claim 2
Dependent Claim
48 words
A ceramic structure comprising a ceramic substrate capable of withstanding a temperature of at least about 1,200° C. and -1,500° C. and a ceramic composite coating thereon, said coating comprising a matrix phase of silicon carbide and an intermetallic phase of titanium disilicide uniformly dispersed within said matrix.
Claim 3
Dependent Claim
42 words
The ceramic structure claimed in claim 1 wherein said coating is of a thickness in the range of about 10 to 300 micrometers and wherein the coating is characterized by a fracture toughness in the range of about 6.5 to 7.0 MPa√m.
Claim 4
Dependent Claim
23 words
The ceramic structure claimed in claim 1 wherein the dispersion of titanium disilicide provides about 15 to 60 wt. % of said coating.
Claim 5
Independent Claim
92 words
A method for fabricating a ceramic structure provided with a ceramic composite coating thereon formed by chemical vapor deposition, comprising the steps of contacting a ceramic substrate capable of withstanding a temperature of at least about 1,200° C.-1,500° C. with the gaseous mixture of methyltrichlorosilane, titanium tetrachloride and the carrier gas of hydrogen, and heating the substrate and gaseous mixture to a temperature sufficiently to thermally decompose the methyltrichlorosilane and the titanium tetrachloride to effect the codeposition of a matrix phase of silicon carbide and a dispersed intermetallic phase of titanium disilicide.
Claim 6
Independent Claim
92 words
A method for fabricating a ceramic structure provided with a ceramic composite coating thereon formed by chemical vapor deposition, comprising the steps of contacting a ceramic substrate capable of withstanding a temperature of at least about 1,200° C.-1,500° C. with the gaseous mixture of methyltrichlorosilane, titanium tetrachloride and the carrier gas of hydrogen, and heating the substrate and gaseous mixture to a temperature sufficiently to thermally decompose the methyltrichlorosilane and the titanium tetrachloride to effect the codeposition of a matrix phase of silicon carbide and a dispersed intermetallic phase of titanium disilicide.
Claim 7
Dependent Claim
16 words
The method claimed in claim 4 wherein said temperature is the range of about 1200°-1500° C.
Claim 8
Dependent Claim
26 words
The method claimed in claim 4 wherein the gaseous mixture contains about 3-10 vol. % methyltrichlorosilane, about 1-4 vol. % titanium tetrachloride and the balance hydrogen.
Claim 9
Dependent Claim
31 words
The method claimed in claim 4 wherein the codeposition is maintained for a sufficient duration to provide a coating of a thickness in the range of about 10 to 300 micrometers.
References Cited (Backward Citations)
US4039997A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-30 | 1989-12-30 | 1990-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-30 | 1993-12-30 | 1994-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-30 | 1997-12-30 | 1998-07-01 | $7700.00 | Window Closed / Lapsed |