US3897358A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polycrystalline ceramic lasers
Assignee: General Electric Co
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Filing: 1973-12-14
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Granted: 1975-07-29
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Expires: 1993-12-14
Abstract
Abstract A method of making a laser body from a high density yttria-based ceramic material is provided. The method involves forming an aqueous solution containing water soluble salts of yttrium, thorium and neodymium, coprecipitating the cations from solution with oxalic acid, recovering the oxalate precipitate in the form of a purified dried powder, calcining the powder to convert the oxalates to the oxides, particulating the oxides in a rubberlined ball mill, pressing the powdered oxides into a ''''green body'''', sintering the ''''green body'''' in a hydrogen atmosphere and rapidly cooling the sintered body to form an improved lasing ceramic material.
Inventors
- 👤 Charles D Greskovich
- 👤 Walter L Roth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:52
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/14; H01S3/16; H01S3/17; C; C04; C04B; C04B35/00; C04B35/50; C04B35/505; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/7767; C09K11/7769
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
171 words
A METHOD OF MAKING A CERAMIC LASER CONSISTING ESSENTIALLY IN MOLE PERCENT AS CALCULATED FROM THE BATCH ON THE OXIDE BASIS OF 81-97.5 PERCENT Y2O3, 2-15 PERCENT THO2 AND 0.5-4 PERCENT ND2O3, SAID METHOD COMPRISING THE STEPS OF: A. FORMING AN AQUEOUS SOLUTION CONSISTING ESSENTIALLY OF THE WATER SOLUBLE SALTS OF YTRIUM, THORIUM, AND NEODYMIUM IN AN AMOUNT CORRESPONDING TO THE PERCENT OF OXIDES SET FORTH ABOVE: B. COPRECIPITATING THE CATIONS FROM SOLUTION WITH OXAILIC ACID TO FORM AN INSOLUBLE MIXED PRECIPITATE OF YTRIUM OXALATE, THORIUM OXALATE AND NEODYMIUM OXALATE: C. RECOVERING THE OXALATE PRECIPITATE: D. CALCINING THE PRECIPITATE TO CONVERT THEOXALATES TO THE OXIDES: E. PARTICULATING THE OXIDES IN A VULCANIZED RUBBER-LINED BALL MILL: F. PRESSING THE POWDERED OXIDES INTO A GREEN BODY: G. SINTERING THE GREEN BODY IN A HYDROGEN ATMOSPHERE AT A TEMPERATURE OF ABOUT 1900*-2200*C:AND H. RAPIDLY COOLING THE SINTERED BODY AT A RATE OF 10*-80*C PER MINUTE BETWEEN THE SINTERNG TEMPERATURE AND 800*C AND COOLING THE BODY TO ROOM TEMPERATURE TO FORM A POLYCRYSTALLINE CERAMIC LASER.
Claim 2
Independent Claim
171 words
A METHOD OF MAKING A CERAMIC LASER CONSISTING ESSENTIALLY IN MOLE PERCENT AS CALCULATED FROM THE BATCH ON THE OXIDE BASIS OF 81-97.5 PERCENT Y2O3, 2-15 PERCENT THO2 AND 0.5-4 PERCENT ND2O3, SAID METHOD COMPRISING THE STEPS OF: A. FORMING AN AQUEOUS SOLUTION CONSISTING ESSENTIALLY OF THE WATER SOLUBLE SALTS OF YTRIUM, THORIUM, AND NEODYMIUM IN AN AMOUNT CORRESPONDING TO THE PERCENT OF OXIDES SET FORTH ABOVE: B. COPRECIPITATING THE CATIONS FROM SOLUTION WITH OXAILIC ACID TO FORM AN INSOLUBLE MIXED PRECIPITATE OF YTRIUM OXALATE, THORIUM OXALATE AND NEODYMIUM OXALATE: C. RECOVERING THE OXALATE PRECIPITATE: D. CALCINING THE PRECIPITATE TO CONVERT THEOXALATES TO THE OXIDES: E. PARTICULATING THE OXIDES IN A VULCANIZED RUBBER-LINED BALL MILL: F. PRESSING THE POWDERED OXIDES INTO A GREEN BODY: G. SINTERING THE GREEN BODY IN A HYDROGEN ATMOSPHERE AT A TEMPERATURE OF ABOUT 1900*-2200*C:AND H. RAPIDLY COOLING THE SINTERED BODY AT A RATE OF 10*-80*C PER MINUTE BETWEEN THE SINTERNG TEMPERATURE AND 800*C AND COOLING THE BODY TO ROOM TEMPERATURE TO FORM A POLYCRYSTALLINE CERAMIC LASER.
Claim 3
Dependent Claim
17 words
The method of claim 1, wherein the water soluble salts are in the form of the nitrates.
Claim 4
Dependent Claim
26 words
The method of claim 2, wherein the ceramic laser consists essentially of 89 mole percent yttria, 10 mole percent thoria, and 1 mole percent neodymium oxide.
Claim 5
Dependent Claim
35 words
The method of claim 1, wherein the sintering step is performed at a temperature of 2000*-2200* C. and the green body is raised to the sintering temperature at a rate of 20*-900* C. per hour.
Claim 6
Dependent Claim
33 words
The methOd of claim 1, wherein the sintered body is heated to a temperature of about 2170* C. and then cooled to 800* C. at a rate of about 20* C. per minute.
Claim 7
Dependent Claim
52 words
The method of claim 1, wherein the sintered body is initially slowly cooled to room temperature, then reheated to about 2000*-2200* C. for a time sufficient to establish equilibrium, and finally subjected to the rapid cooling step at a rate of 10*-80* C. per minute between the reheating temperature and 800* C.
Claim 8
Dependent Claim
27 words
The method of claim 2, wherein the ceramic laser consists essentially of about 94 mole percent yttria, 5 mole percent thoria, and 1 mole percent neodymium oxide.
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) | 1978-07-28 | 1979-01-27 | 1979-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-28 | 1983-01-27 | 1983-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-28 | 1987-01-27 | 1987-07-29 | $7700.00 | Window Closed / Lapsed |