US4012204A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aluminum alloy reinforced with alumina fibers and lithium wetting agent
Assignee: EIDP Inc
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Filing: 1975-09-22
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Granted: 1977-03-15
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Expires: 1995-09-22
Abstract
Abstract A composite reinforced with polycrystalline alumina fibers in a matrix of an aluminum alloy containing 0.5-5.5% by weight of the matrix of lithium is prepared by infiltrating alumina fibers with a molten alloy containing aluminum and 1-8% by weight of lithium for a time sufficient to form a reaction sheath on the fibers of a thickness less than about 15% of the total fiber diameter.
Inventors
- 👤 Paul Gordon Riewald
- 👤 William Henry Krueger
- 👤 Ashok Kumar Dhingra
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:42
CPC Classifications
C; C22; C22C; C22C47/00; C22C47/08; C22C49/00; C22C49/02; C22C49/04; C22C49/06; B; B22; B22F; B22F2998/00; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/923; Y10S428/924; Y10T; Y10T428/00; Y10T428/12; Y10T428/12486; Y10T428/26; Y10T428/268
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
56 words
A composite reinforced with 10-80 volume percent of polycrystalline alumina fibers and having a matrix of an aluminum alloy containing about 0.5-5.5% by weight of lithium in which the fibers have a reaction sheath of a thickness less than 15% of the total fiber diameter and the composite has a porosity of less than about 10%.
Claim 2
Dependent Claim
56 words
A composite reinforced with 10-80 volume percent of polycrystalline alumina fibers and having a matrix of an aluminum alloy containing about 0.5-5.5% by weight of lithium in which the fibers have a reaction sheath of a thickness less than 15% of the total fiber diameter and the composite has a porosity of less than about 10%.
Claim 3
Dependent Claim
17 words
The composite of claim 1 wherein the matrix contains at least about 60% by weight of aluminum.
Claim 4
Dependent Claim
17 words
The composite of claim 2 in which the matrix contains at least 90% by weight of aluminum.
Claim 5
Dependent Claim
30 words
The composite of claim 2 wherein the matrix contains up to about 10% by weight of one or more metals capable of being alloyed with aluminum in addition to lithium.
Claim 6
Dependent Claim
14 words
The composite of claim 4 wherein the additional metal is magnesium, zinc or silicon.
Claim 7
Dependent Claim
15 words
The composite of claim 1 wherein the reaction sheath is less than 0.5 micron thick.
Claim 8
Dependent Claim
12 words
The composite of claim 1 having a porosity of 5% or less.
Claim 9
Dependent Claim
12 words
The composite of claim 7 having a porosity of less than 2%.
Claim 10
Dependent Claim
14 words
The composite of claim 1 containing about 15-70 volume percent of polycrystalline alumina fibers.
Claim 11
Dependent Claim
16 words
The composite of claim 1 containing about 30-60 volume percent of continuous filaments of polycrystalline alumina.
Claim 12
Dependent Claim
15 words
The composite of claim 1 containing about 15-30 volume percent of discontinuous polycrystalline alumina fibers.
Claim 13
Dependent Claim
15 words
The composites of claim 11 wherein the fibers have a minimum length of 0.1 mm.
Claim 14
Dependent Claim
22 words
The composite of claim 1 wherein the polycrystalline alumina fibers contain at least 60% by weight of Al 2 O 3 .
Claim 15
Dependent Claim
18 words
The composite of claim 13 wherein the alumina fibers contain at least 80% by weight of aluminum oxide.
Claim 16
Dependent Claim
19 words
The composite of claim 13 wherein the polycrystalline alumina fibers contain at least 95% Al 2 O 3 .
Claim 17
Dependent Claim
18 words
The composite of claim 13 wherein the Al 2 O 3 is in the form of alpha alumina.
Claim 18
Dependent Claim
18 words
The composite of claim 14 wherein the Al 2 O 3 is in the form of alpha alumina.
Claim 19
Dependent Claim
27 words
The composite of claim 13 wherein the fibers contain refractory oxides, refractory oxide systems or mixtures thereof and have a melting point of at least 1000° C.
Claim 20
Dependent Claim
32 words
The composite of claim 13 wherein the fibers have a diameter of 15-30 μ, a tensile strength of at least 100,000 psi and a Young's modulus of at least 20 million psi.
Claim 21
Dependent Claim
38 words
The composite of claim 9 having a longitudinal modulus of at least 15 × 10 6 psi and a flexural strength at least equal to the product of 1900 psi and the volume of the fibers in %.
Claim 22
Dependent Claim
11 words
The composite of claim 9 having a strain-to-failure greater than 0.2%.
Claim 23
Dependent Claim
16 words
The composite of claim 9 having a short beam shear strength of at least 7000 psi.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-03-14 | 1980-09-13 | 1981-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-14 | 1984-09-13 | 1985-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-14 | 1988-09-13 | 1989-03-15 | $7700.00 | Window Closed / Lapsed |