US3709667A
Expired / Lapsed
US
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Dispersion strengthening of platinum group metals and alloys
Assignee: Johnson Matthey PLC
•
Filing: 1971-01-19
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Granted: 1973-01-09
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Expires: 1991-01-19
Abstract
Abstract This specification describes a method of producing dispersion strengthened metals or alloys by alloying the metal or alloy with a minor amount of a material capable of forming a stable refractory compound. The so formed alloy is converted to granular or powder form and the powder is then cold worked prior to exposing the cold worked and so deformed granules to a gas at a temperature so as to form a stable refractory compound within the metal or alloy. Thereafter the metal or alloy particles are compacted and sintered to form an ingot.
Inventors
- 👤 G Selman
- 👤 A Darling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:47
CPC Classifications
C; C22; C22C; C22C1/00; C22C1/10; C22C1/1078; Y; Y10; Y10S; Y10S75/00; Y10S75/95; Y10S75/951
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
15 words
A method according to claim 1 wherein the stable refractory compound formed comprises an oxide.
Claim 2
Dependent Claim
32 words
A method according to claim 2 wherein the stable refractory oxide is formed by heating the deformed particles containing the additive material in an oxygen containing atmosphere at a relatively low temperature.
Claim 3
Dependent Claim
26 words
A method according to claim 3 wherein the particles are heated in the atmosphere which is a constant stream of oxygen-containing gas passing through the particles.
Claim 4
Dependent Claim
64 words
A method according to claim 2 wherein the stable refractory compound formed is selected from an oxide of beryllium, magnesium, aluminum, silicon, thorium, uranium, a metal in the first transition series comprising the elements calcium to manganese, a metal in the second transition series comprising the elements strontium to niobium, and a metal in the third transition series comprising the elements barium to tantalum.
Claim 5
Dependent Claim
24 words
A method according to claim 2 wherein the oxide formed has a high negative free energy of formation of the order of -160K.cal./gm. mole.
Claim 6
Dependent Claim
18 words
A method according to claim 1 wherein the granules or particles are deformed into flakes in a ball-mill.
Claim 7
Dependent Claim
49 words
A method according to claim 1 wherein the degree of cold working to which the granules are subjected and the quantity of additive oxidizable material contained within the alloy are such as on subsequent heating to provide for simultaneous processes of internal oxidation and recrystallization in the deformed granules.
Claim 8
Dependent Claim
18 words
A method according to claim 1 wherein the particles are made from an alloy of platinum and zirconium.
Claim 9
Dependent Claim
17 words
A method according to claim 9 wherein the platinum-zirconium alloy contains between 0.05 and 5 wt.% zirconium.
Claim 10
Dependent Claim
17 words
A method according to claim 10 wherein the platinum-zirconium alloy contains between 0.5 and 2 wt.% zirconium.
Claim 11
Dependent Claim
25 words
A method according to claim 1 which includes the additional step of forging the sintered compact at an elevated temperature to increase the density thereof.
Claim 12
Dependent Claim
20 words
A method according to claim 12 wherein the compact is sintered at a temperature between 1200* C. and 1300* C.
Claim 13
Dependent Claim
35 words
A method according to claim 1 wherein the conversion of the alloy into particles is effected by forming the alloy into wire and subsequently flame-spraying the wire into a non-volatile liquid such as distilled water.
Claim 14
Dependent Claim
17 words
A method according to claim 1 wherein recrystallization is caused with or without the addition of heat.
Claim 15
Dependent Claim
30 words
A dispersion strengthened metal of the platinum group or an alloy thereof comprising an internally oxidized mass of granules of said metal or alloy alloyed with a stable refractory oxide.
Claim 16
Dependent Claim
19 words
The dispersion strengthened metal of claim 16 wherein the metal is platinum alloyed with a minor quantity of zirconia.
Claim 17
Dependent Claim
24 words
A dispersion strengthened metal or alloy as claimed in claim 16 and forged into bar form to increase the density of the sintered granules.
Claim 18
Dependent Claim
22 words
The metal of claim 16 wherein the internally oxidized granules are in a compacted and sintered form after the said internal oxidation.
Claim 19
Independent Claim
118 words
A method of dispersion strengthening a metallic material which at least prior to dispersion strengthening is resistant to oxidation and diffusion of gaseous oxygen therethrough and Which is selected from the group consisting of platinum group metals, platinum group metal alloys, gold, gold alloys and alloys containing nickel and chromium, by internal oxidation which consists in alloying the metallic material with a minor amount of an additive metal capable of forming a stable refractory oxide, converting the so-formed alloy into granules, deforming the granules by cold working, heating the deformed granules in an atmosphere containing oxygen at a temperature such as to form said stable refractory oxide within the metal granules and compacting and sintering the treated granules.
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) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |