US5032550A
Expired / Lapsed
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High impact resistant ceramic composite
Assignee: Alcoa Corp
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Filing: 1989-10-13
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Granted: 1991-07-16
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Expires: 2009-10-13
Abstract
Abstract A ceramic material and a method of forming a ceramic material which possesses a high impact resistance. The material comprises: (a) a first continuous phase of beta -SiC; and (b) a second phase of about 25-40 vol % TiB2. Al2O3 is preferably used as a densification aid. The material is formed by hot-pressing the mixture at a temperature from greater than about 1800 DEG C. to less than the transition temperature of beta -SiC to alpha -SiC. The hot-pressing is performed at a pressure of about 2000 psi to about 4000 psi in an inert atmosphere for several hours and results in the formation of a two phase sintered ceramic composite material.
Inventors
- 👤 James A. Derkacy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:11
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/575
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
71 words
A method of forming a ceramic material having a high impact resistance, said method comprising the steps of: (a) forming a mixture of 60-75 vol. % β-SiC, 25-40 vol. % TiB 2 and 0.5-3.0 wt. % of Al 2 O 3 as a densification aid; and (b) hot pressing said mixture at a temperature less than the transition temperature of β-SiC to α-SiC to form a mixed phase β-SiC/TiB 2 material.
Claim 2
Independent Claim
71 words
A method of forming a ceramic material having a high impact resistance, said method comprising the steps of: (a) forming a mixture of 60-75 vol. % β-SiC, 25-40 vol. % TiB 2 and 0.5-3.0 wt. % of Al 2 O 3 as a densification aid; and (b) hot pressing said mixture at a temperature less than the transition temperature of β-SiC to α-SiC to form a mixed phase β-SiC/TiB 2 material.
Claim 3
Dependent Claim
34 words
The method according to claim 1 wherein said step of forming a mixture β-SiC and TiB 2 includes: mixing β-SiC powder having an average particle size between about 0.3 microns and about 1.5 microns.
Claim 4
Dependent Claim
36 words
The method according to claim 1 wherein said step of forming a mixture of β-SiC and TiB 2 includes: mixing TiB 2 powder having an average particle size between about 3.0 microns and about 8.0 microns.
Claim 5
Dependent Claim
40 words
The method according to claim 1 wherein said step of forming a mixture of β-SiC and TiB 2 includes: wet milling said mixture in a nonaqueous solution; drying said mixture in air; and screening said mixture to minus 20 mesh.
Claim 6
Dependent Claim
29 words
The method according to claim 1 wherein said step of hot pressing said mixture includes heating said unreacted mixture to a temperature from about 1880° C. to 2000° C.
Claim 7
Dependent Claim
29 words
The method according to claim 1 wherein said step of hot pressing said unreacted mixture includes maintaining pressure of from about 2000 to about 4000 psi on said mixture.
Claim 8
Dependent Claim
47 words
A hot pressed ceramic material having an improved impact resistance, the material comprising: (a) 60-75 vol. % of a continuous SiC matrix which is β-SiC; (b) 25-40 vol. % of a second TiB 2 phase; and (c) 0.5 to 3.0 wt. % Al 2 O 3 .
Claim 9
Dependent Claim
47 words
A hot pressed ceramic material having an improved impact resistance, the material comprising: (a) 60-75 vol. % of a continuous SiC matrix which is β-SiC; (b) 25-40 vol. % of a second TiB 2 phase; and (c) 0.5 to 3.0 wt. % Al 2 O 3 .
Claim 10
Dependent Claim
20 words
The material of claim 7 in which said TiB 2 phase contains agglomerates of at least 20 microns in length.
Claim 11
Dependent Claim
13 words
The material of claim 7 in which said TiB 2 phase is semi-continuous.
Claim 12
Dependent Claim
34 words
A ceramic composite armor material comprising: (a) a continuous matrix of 60-75 vol. % β-SiC; (b) 25-40 vol. % TiB 2 agglomerates; and (c) 0.5 to 3.0 wt. % Al 2 O 3 .
Claim 13
Dependent Claim
34 words
A ceramic composite armor material comprising: (a) a continuous matrix of 60-75 vol. % β-SiC; (b) 25-40 vol. % TiB 2 agglomerates; and (c) 0.5 to 3.0 wt. % Al 2 O 3 .
Claim 14
Dependent Claim
18 words
The material of claim 10 in which said TiB 2 agglomerates are at least 20 microns in length.
Claim 15
Dependent Claim
15 words
The material of claim 10 in which said TiB 2 agglomerates form a semi-continuous phase.
Claim 16
Independent Claim
66 words
A method of forming a ceramic armor material, said method comprising the steps of: (a) forming a mixture of 60-75 vol. % β-SiC, 25-40 vol. % TiB 2 and 0.5 to 3.0 wt. % of Al 2 O 3 ; and (b) hot pressing said mixture at a temperature less than the transition temperature of β-SiC to α-SiC to form a mixed phase β-SiC/TiB 2 material.
Claim 17
Independent Claim
66 words
A method of forming a ceramic armor material, said method comprising the steps of: (a) forming a mixture of 60-75 vol. % β-SiC, 25-40 vol. % TiB 2 and 0.5 to 3.0 wt. % of Al 2 O 3 ; and (b) hot pressing said mixture at a temperature less than the transition temperature of β-SiC to α-SiC to form a mixed phase β-SiC/TiB 2 material.
Claim 18
Dependent Claim
51 words
The method according to claim 13 wherein said step of forming a mixture β-SiC and TiB 2 includes: mixing β-SiC powder having an average particle size between about 0.3 microns and about 1.5 microns and TiB 2 powder having an average particle size between about 3.0 microns and about 8.0 microns.
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) | 1994-07-15 | 1995-01-14 | 1995-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-15 | 1999-01-14 | 1999-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-15 | 2003-01-14 | 2003-07-16 | $7700.00 | Window Closed / Lapsed |