US4036599A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polycrystalline alumina fibers as reinforcement in magnesium matrix
Assignee: EIDP Inc
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Filing: 1975-08-15
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Granted: 1977-07-19
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Expires: 1995-08-15
Abstract
Abstract A fiber reinforced metal composite comprising magnesium or a magnesium alloy containing substantially aligned, polycrystalline alumina fibers which have certain surface roughness characteristics and contain at least 80% Al 2 O 3 by weight.
Inventors
- 👤 Ashok Kumar Dhingra
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:48
CPC Classifications
C; C22; C22C; C22C49/00; C22C49/02; C22C49/04; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/923; Y10S428/924; Y10S428/925; Y10T; Y10T428/00; Y10T428/12; Y10T428/12444
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
116 words
A fiber-reinforced metal composite consisting essentially of A. substantially aligned, continuous, polycrystalline alumina fibers which are substantially all alpha alumina and have 1. a diameter of about 15 to 30 microns, 2. a microscopic roughness height between 0.20 and 0.40 micron, 3. a microscopic roughness period between 0.8 and 1.5 micron, and 4. a tensile strength of at least about 125,000 pounds per square inch after removal from the composite, said fibers comprising between about 50 and 80 percent of the composite by volume; and B. a matrix of magnesium or magnesium alloy containing at least 90 percent magnesium by weight and having an average grain size in the composite of less than about 4 microns.
Claim 2
Dependent Claim
116 words
A fiber-reinforced metal composite consisting essentially of A. substantially aligned, continuous, polycrystalline alumina fibers which are substantially all alpha alumina and have 1. a diameter of about 15 to 30 microns, 2. a microscopic roughness height between 0.20 and 0.40 micron, 3. a microscopic roughness period between 0.8 and 1.5 micron, and 4. a tensile strength of at least about 125,000 pounds per square inch after removal from the composite, said fibers comprising between about 50 and 80 percent of the composite by volume; and B. a matrix of magnesium or magnesium alloy containing at least 90 percent magnesium by weight and having an average grain size in the composite of less than about 4 microns.
Claim 3
Dependent Claim
26 words
The composite of claim 1 enclosed in a metallic sheath having a thickness between about 5 and 25 percent of the diameter of the unsheathed composite.
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) | 1980-07-18 | 1981-01-17 | 1981-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-18 | 1985-01-17 | 1985-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-18 | 1989-01-17 | 1989-07-19 | $7700.00 | Window Closed / Lapsed |