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US3873307A
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Process for the preparation of yttrium-silicon compounds or master alloys by silicon carbide reduction of yttria
Assignee: United States Department of the Interior
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Filing: 1973-11-05
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Granted: 1975-03-25
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Expires: 1993-11-05
Abstract
Abstract A process for the manufacture of yttrium-silicon master alloys. Using silicon carbide as a reductant, both yttria and silicon carbide are mixed, placed in a crucible and heated for a period of time in a vacuum furnace whereby the mixture is sintered, yielding the desired product and CO and CO2 gases. The charge is maintained under a dynamic vacuum during heating, holding, and cooling with continuous removal of gaseous reaction products.
Inventors
- 👤 Jr Edward Morrice
- 👤 Norman J Whisler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:58
CPC Classifications
C; C22; C22C; C22C1/00; C22C1/02; C22C1/03; C22B; C22B5/00; C22B5/02; C22B5/06; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/122
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
75 words
A PROCESS FOR THE PREPARATION OF YTTRIUM-SILICON COMPOUNDS OR MASTER ALLOYS BY SILICON-CARBIDE REDUCTION OF YTTRIA COMPRISING THE STEPS: A. MIXING A CHARGE CONSISTING ESSENTIALLY OF YTTRIA AND SILICON CARBIDE; B. PLACING SAID CHARGE IN A VACUUM FURNACE; C. SINTERING AND HEATING SAID CHARGE AT A TEMPERATURE OF FROM 1,200* TO 2,500*C UNDER DYNAMIC VACUUM CONDITIONS; WHEREBY THE YTTRIA IS REDUCED AND A YTTRIUM-SILICON COMPOUND IS PRODUCED!; D. COOLING SAID SINTERED CHARGE UNDER VACUUM CONDITIONS.
Claim 2
Dependent Claim
75 words
A PROCESS FOR THE PREPARATION OF YTTRIUM-SILICON COMPOUNDS OR MASTER ALLOYS BY SILICON-CARBIDE REDUCTION OF YTTRIA COMPRISING THE STEPS: A. MIXING A CHARGE CONSISTING ESSENTIALLY OF YTTRIA AND SILICON CARBIDE; B. PLACING SAID CHARGE IN A VACUUM FURNACE; C. SINTERING AND HEATING SAID CHARGE AT A TEMPERATURE OF FROM 1,200* TO 2,500*C UNDER DYNAMIC VACUUM CONDITIONS; WHEREBY THE YTTRIA IS REDUCED AND A YTTRIUM-SILICON COMPOUND IS PRODUCED!; D. COOLING SAID SINTERED CHARGE UNDER VACUUM CONDITIONS.
Claim 3
Dependent Claim
14 words
The process of claim 1 wherein the sintering temperature is from 1,600* to 2,500*C.
Claim 4
Dependent Claim
21 words
The process of claim 2, wherein the charge of yttria and silicon carbide is in a molar ratio of about 1:3.
Claim 5
Dependent Claim
18 words
The process according to claim 1, wherein the source of yttria is rare-earth oxides high in Y2O3 content.
Claim 6
Dependent Claim
89 words
A process for the preparation of yttrium-silicon compounds or master alloys by silicon-carbide reduction of yttria comprising the steps: a. mixing a charge consisting essentially of yttria and silicon carbide in a molar ratio of about 1:3; b. placing said charge in a vacuum furnace; c. sintering and holding said charge at a temperature of from about 1,600* to 2,500*C for a period of time sufficient to reduce the yttria under vacuum conditions; and d. cooling said charge under vacuum conditions whereby a master alloy of Y-Si is produced.
Claim 7
Dependent Claim
89 words
A process for the preparation of yttrium-silicon compounds or master alloys by silicon-carbide reduction of yttria comprising the steps: a. mixing a charge consisting essentially of yttria and silicon carbide in a molar ratio of about 1:3; b. placing said charge in a vacuum furnace; c. sintering and holding said charge at a temperature of from about 1,600* to 2,500*C for a period of time sufficient to reduce the yttria under vacuum conditions; and d. cooling said charge under vacuum conditions whereby a master alloy of Y-Si is produced.
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) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |