US4410635A
Expired / Lapsed
US
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Discontinuous silicon carbide fiber reinforced ceramic composites
Assignee: RTX Corp
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Filing: 1982-02-05
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Granted: 1983-10-18
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Expires: 2002-02-05
Abstract
Abstract Discontinuous silicon carbide fiber reinforced ceramic composites are disclosed having high strength, fracture toughness, and oxidative stability, even in high temperature oxidative environments. Disclosed composites include silicon carbide fiber reinforced aluminosilicate, lithium aluminosilicate, barium aluminosilicate, magnesium aluminosilicate, and combinations thereof. Flexural strengths in excess of 20,000 psi (138 MPa) at temperatures in excess of 1000° C. are attainable with such composites. The composite is formed by starting with the ceramic matrix material in the glassy state and converting it from the glassy state to the ceramic state after densification of the composite.
Inventors
- 👤 John J. Brennan
- 👤 Karl M. Prewo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:22
CPC Classifications
C; C03; C03C; C03C14/00; C03C14/002; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18; C04B35/19; C04B35/195; C04B35/622; C04B35/64; C04B35/645; C04B35/71; C04B35/78; C04B35/80; C03C2214/00; C03C2214/02; C03C2214/20; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3201; C04B2235/3203; C04B2235/3205; C04B2235/3206; C04B2235/3215; C04B2235/36; C04B2235/50; C04B2235/52; C04B2235/5208; C04B2235/5216; C04B2235/524; C04B2235/5244; C04B2235/526; C04B2235/5268; C04B2235/54; C04B2235/5418; C04B2235/5436; C04B2235/70; C04B2235/72; C04B2235/94; C04B2235/96; C04B2235/9669; C04B2235/9684
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
83 words
A silicon carbide fiber reinforced ceramic composite consisting essentially of about 15% to about 50% by volume high strength and high modulus of elasticity discontinuous silicon carbide fibers laid up in substantially in-plane random orientation in a substantially titanium-free glass-ceramic matrix selected from the group consisting of lithium aluminosilicate, magnesium aluminosilicate, barium aluminosilicate, aluminosilicate, and combinations thereof, so as to produce strength and fracture toughness properties greater than that of the matrix at temperatures in excess of 800° C. in an oxidizing environment.
Claim 2
Dependent Claim
83 words
A silicon carbide fiber reinforced ceramic composite consisting essentially of about 15% to about 50% by volume high strength and high modulus of elasticity discontinuous silicon carbide fibers laid up in substantially in-plane random orientation in a substantially titanium-free glass-ceramic matrix selected from the group consisting of lithium aluminosilicate, magnesium aluminosilicate, barium aluminosilicate, aluminosilicate, and combinations thereof, so as to produce strength and fracture toughness properties greater than that of the matrix at temperatures in excess of 800° C. in an oxidizing environment.
Claim 3
Dependent Claim
26 words
The composite of claim 1 having a flexural strength greater than 10,000 psi (68.8 MPa) at temperatures in excess of 800° C. in an oxidizing environment.
Claim 4
Dependent Claim
26 words
The composite of claim 1 having a flexural strength greater than 20,000 psi (138 MPa) at temperatures in excess of 800° C. in an oxidizing environment.
Claim 5
Dependent Claim
25 words
The composite of claim 1 having a fracture toughness greater than 3 MPa/m 3/2 at temperatures in excess of 800° C. in an oxidizing environment.
Claim 6
Dependent Claim
25 words
The composite of claim 1 having a fracture toughness greater than 5 MPa/m 3/2 at temperatures in excess of 800° C. in an oxidizing environment.
Claim 7
Dependent Claim
80 words
A silicon carbide fiber reinforced ceramic composite consisting essentially of about 15% to about 50% by volume high strength, high modulus of elasticity silicon carbide fibers having an average length of about 1 cm to about 3 cm laid up in substantially in-plane random orientation in a substantially titanium-free glass-ceramic matrix of lithium aluminosilicate, magnesium aluminosilicate, barium aluminosilicate, aluminosilicate, and combinations thereof, producing a composite with flexural strength and fracture touchness properties greater than the ceramic matrix at elevated temperatures.
Claim 8
Dependent Claim
80 words
A silicon carbide fiber reinforced ceramic composite consisting essentially of about 15% to about 50% by volume high strength, high modulus of elasticity silicon carbide fibers having an average length of about 1 cm to about 3 cm laid up in substantially in-plane random orientation in a substantially titanium-free glass-ceramic matrix of lithium aluminosilicate, magnesium aluminosilicate, barium aluminosilicate, aluminosilicate, and combinations thereof, producing a composite with flexural strength and fracture touchness properties greater than the ceramic matrix at elevated temperatures.
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) | 1986-10-17 | 1987-04-18 | 1987-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-17 | 1991-04-18 | 1991-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-17 | 1995-04-18 | 1995-10-18 | $7700.00 | Window Closed / Lapsed |