Patent US3713901A successfully refreshed from Google Patents.
US3713901A
Expired / Lapsed
US
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Oxidation resistant refractory alloys
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1970-04-20
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Granted: 1973-01-30
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Expires: 1990-04-20
Abstract
Abstract This invention relates to high-temperature, oxidation-resistant refractory materials or alloys and to a method of preparing said alloys which have an outer skin containing at least one noble metal, e.g., platinum, and/or silver, in amounts greater than the amount of noble metal present in the alloy beneath said skin. The alloy comprises at least one noble metal selected from the group consisting of platinum, gold, silver, rhodium, iridium and palladium. The noble metal is added in amounts ranging from 0.1 to 15% by weight of the total composition to hafnium or to hafnium containing from about 0 to 50 percent by weight of zirconium, and heated to temperatures ranging from about 1000*F to 3800*F in an oxidizing atmosphere.
Inventors
- 👤 M Appel
- 👤 J Blumenthal
- 👤 J Ogren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:07
CPC Classifications
C; C23; C23C; C23C8/00; C23C8/06; C23C8/08; C23C8/10; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12806; Y10T428/12812
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
113 words
A refractory alloy having an outer metallic skin resistant to oxidation at high temperatures which contains at least one noble metal in an amount greater than the amount of noble metal present in the alloy beneath the skin; said skin formed by subjecting the alloy to temperatures ranging from about 1000*F to 3800*F in an oxidizing atmosphere for a period ranging from about one-sixtieth to 60 hours; said alloy consisting essentially 35 to 99.9 percent by weight of hafnium, 0 to 50 percent by weight of zirconium, and 0.1 to 15 percent by weight of at least one noble metal selected from the group consisting of platinum, gold, silver, rhodium, iridium, and palladium.
Claim 2
Dependent Claim
113 words
A refractory alloy having an outer metallic skin resistant to oxidation at high temperatures which contains at least one noble metal in an amount greater than the amount of noble metal present in the alloy beneath the skin; said skin formed by subjecting the alloy to temperatures ranging from about 1000*F to 3800*F in an oxidizing atmosphere for a period ranging from about one-sixtieth to 60 hours; said alloy consisting essentially 35 to 99.9 percent by weight of hafnium, 0 to 50 percent by weight of zirconium, and 0.1 to 15 percent by weight of at least one noble metal selected from the group consisting of platinum, gold, silver, rhodium, iridium, and palladium.
Claim 3
Dependent Claim
37 words
The refractory alloy of claim 1 wherein said skin is formed by subjecting the alloy to temperatures ranging from about 1500*F to 3000*F in an oxidizing atmosphere for a period ranging from about one-sixtieth to 60 hours.
Claim 4
Dependent Claim
29 words
The refractory alloy of claim 2 wherein the period for subjecting the alloy to the oxidizing atmosphere To form the metallic skin is decreased as the temperature is increased.
Claim 5
Dependent Claim
28 words
The refractory alloy of claim 1 wherein at least one of the noble metals is present in an amount ranging from about 0.5 to 10 percent by weight.
Claim 6
Dependent Claim
17 words
The refractory alloy of claim 4 wherein at least two noble metals are present in the alloy.
Claim 7
Dependent Claim
16 words
The refractory alloy of claim 4 wherein at least one of the noble metals is platinum.
Claim 8
Dependent Claim
16 words
The refractory alloy of claim 4 wherein at least one of the noble metals is silver.
Claim 9
Dependent Claim
110 words
A refractory alloy having an outer metallic skin resistant to oxidation at high temperatures; containing at least one noble metal in an amount greater than the amount of noble metal present in the alloy beneath said skin, said skin formed by subjecting the alloy to temperatures ranging from about 1500*F to 3000*F in an oxidizing atmosphere for at least one-sixtieth of an hour; said alloy consisting essentially of 35 to 99.9 percent by weight of hafnium, 0 to 50 percent by weight of zirconium, and 0.1 to 15 percent by weight of at least one noble metal selected from the group consisting of platinum, gold, silver, rhodium, iridium, and palladium.
Claim 10
Dependent Claim
110 words
A refractory alloy having an outer metallic skin resistant to oxidation at high temperatures; containing at least one noble metal in an amount greater than the amount of noble metal present in the alloy beneath said skin, said skin formed by subjecting the alloy to temperatures ranging from about 1500*F to 3000*F in an oxidizing atmosphere for at least one-sixtieth of an hour; said alloy consisting essentially of 35 to 99.9 percent by weight of hafnium, 0 to 50 percent by weight of zirconium, and 0.1 to 15 percent by weight of at least one noble metal selected from the group consisting of platinum, gold, silver, rhodium, iridium, and palladium.
Claim 11
Dependent Claim
115 words
A refractory alloy having an outer metallic skin resistant to oxidation at high temperatures which contains at least one noble metal in an amount greater than the amount of noble metal present in the alloy beneath the skin; said skin formed by subjecting the alloy to temperatures ranging from about 1000*F to 3800*F in an oxidizing atmosphere for a period of time sufficient to cause formation of said skin, said alloy consisting essentially 35 to 99.9 percent by weight of hafnium, 0 to 50 percent by weight of zirconium, and 0.1 to 15 percent by weight of at least one noble metal selected from the group consisting of platinum, gold, silver, rhodium, iridium, and palladium.
Claim 12
Dependent Claim
115 words
A refractory alloy having an outer metallic skin resistant to oxidation at high temperatures which contains at least one noble metal in an amount greater than the amount of noble metal present in the alloy beneath the skin; said skin formed by subjecting the alloy to temperatures ranging from about 1000*F to 3800*F in an oxidizing atmosphere for a period of time sufficient to cause formation of said skin, said alloy consisting essentially 35 to 99.9 percent by weight of hafnium, 0 to 50 percent by weight of zirconium, and 0.1 to 15 percent by weight of at least one noble metal selected from the group consisting of platinum, gold, silver, rhodium, iridium, and palladium.
Claim 13
Dependent Claim
120 words
A process for preparing a refractory alloy having an outer metallic skin resistant to oxidation at high temperatures which contains at least one noble metal in an amount greater than the amount of noble metal present in the alloy beneath the skin which comprises forming said skin by subjecting the alloy to temperatures ranging from about 1000*F to 3800*F in an oxidizing atmosphere for a period ranging from about one-sixtieth to 60 hours; said alloy consisting essentially of 35 to 95 percent by weight of hafnium, 5.0 to 50 percent by weight of zirconium and 0.1 to 15 percent by weight of at least one noble metal selected from the group consisting of platinum, gold, silver, rhodium, iridium, and palladium.
Claim 14
Dependent Claim
120 words
A process for preparing a refractory alloy having an outer metallic skin resistant to oxidation at high temperatures which contains at least one noble metal in an amount greater than the amount of noble metal present in the alloy beneath the skin which comprises forming said skin by subjecting the alloy to temperatures ranging from about 1000*F to 3800*F in an oxidizing atmosphere for a period ranging from about one-sixtieth to 60 hours; said alloy consisting essentially of 35 to 95 percent by weight of hafnium, 5.0 to 50 percent by weight of zirconium and 0.1 to 15 percent by weight of at least one noble metal selected from the group consisting of platinum, gold, silver, rhodium, iridium, and palladium.
Claim 15
Dependent Claim
32 words
The process of claim 10 wherein the alloy is subjected to temperatures ranging from about 1500* to 3000*F in an oxidizing atmosphere for a period ranging from about one-sixtieth to 60 hours.
Claim 16
Dependent Claim
36 words
The process of claim 11 wherein the period for subjecting the alloy to an oxidizing atmosphere to form the metallic skin is decreased to one-sixtieth of an hour as the temperature is increased to about 3000*F.
Claim 17
Dependent Claim
59 words
The process of claim 10 wherein the alloy on which the skin is formed consists essentially of 50 to 85 percent by weight of hafnium, 5.0 to 50 percent by weight of zirconium and 0.5 to 10 percent by weight of at least one noble metal selected from the group consisting of platinum, gold, silver, rhodium, iridium, and palladium.
Claim 18
Dependent Claim
14 words
The process of claim 13 wherein the alloy contains at least two noble metals.
Claim 19
Dependent Claim
15 words
The process of claim 13 wherein at least one of the noble metals is platinum.
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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) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |