US3873657A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing highly pure sintered polycrystalline yttrium oxide body having high transparency
Assignee: Hitachi Ltd
•
Filing: 1973-08-27
•
Granted: 1975-03-25
•
Expires: 1993-08-27
Abstract
Abstract When highly pure yttrium oxide is press molded into a desired shape and then the press molded body thus obtained is sintered at an elevated temperature in the presence of a beryllium compound, a sintered polycrystalline yttrium oxide body excellent in transparency is easily obtained at a comparatively low molding pressure and at a comparatively low sintering temperature.
Inventors
- 👤 Gyozo Toda
- 👤 Iwao Matsuyama
- 👤 Yasuo Tsukuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:17
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/50; C04B35/505; Y; Y10; Y10S; Y10S264/00; Y10S264/25
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
82 words
In the method for producing a transparent highly pure sintered polycrystalline body consisting of yttrium oxide having a high in-line transmission for a wide range spectrum from visible-to-far infrared rays, comprising the steps of preparing a press molded body from highly pure yttrium oxide powder and sintering the press molded body in an atmosphere selected from the group consisting of hydrogen and vacuum, the improvement wherein the step of sintering the press molded body is conducted in the presence of beryllium oxide.
Claim 2
Dependent Claim
82 words
In the method for producing a transparent highly pure sintered polycrystalline body consisting of yttrium oxide having a high in-line transmission for a wide range spectrum from visible-to-far infrared rays, comprising the steps of preparing a press molded body from highly pure yttrium oxide powder and sintering the press molded body in an atmosphere selected from the group consisting of hydrogen and vacuum, the improvement wherein the step of sintering the press molded body is conducted in the presence of beryllium oxide.
Claim 3
Independent Claim
209 words
A METHOD FOR PRODUCING A TRANSPARENT HIGHLY PURE SINTERED POLYCRYSTALLINE BODY CONSISTING ESSENTIALLY OF YTTRIUM OXIDE HAVING A HIGH IN-LINE TRANSMISSION FOR A WIDE RANGE SPECTRUM FROM VISIBLE TO FAIR INFRARED RAYS, COMPRISING THE STEPS OF (1) PRESS MOLDING A MIXTURE OF HIGHLY PURE YTTRIUM OXIDE HAVING A PURITY OF AT LEAST 99.9% AND 0.01 TO 1.0% BY WEIGHT, BASED ON YTTRIUM OXIDE AND MEASURED AS BERYLLIUM OXIDE, OF BERYLLIUM OXIDE AND/OR A BERYLLIUM COMPOUND EASILY CONVERTIBLE UNDER SINTERING CONDITIONS TO BERYLLIUM OXIDE UNDER A MOLDING PRESSURE OF AT LEAST 0.3 TON PER SQUARE CENTIMETER TO FORM A MOLDED BODY OF A DESIRED SHAPE, AND (2) SUBJECTING SAID MOLDED BODY TO A SINTERING TREATMENT COMPRISING (A) HEATING THE MOLDED BODY IN A DRY HYDROGEN ATMOSPHERE HAVING A DEW POINT OF ABOUT -5*C. OR LOWER AT A TEMPERATURE 2050* TO 2250*C. FOR AT LEAST ABOUT 30 MINUTES TO THEREBY SINTER THE MOLDED BODY AND (B) REFIRING THE RESULTANT SINTERED BODY IN A HYDROGEN ATMOSPHERE HAVING A DEW POINT OF AT LEAST 0*C. AND MAINTAINED AT 1800* TO 2250*C. FOR AT LEAST ABOUT 10 MINUTES TO THEREBY EFFECT DECOLORATION OF THE SINTERED BODY, WHEREBY A HIGHLY PURE TRANSPARENT POLYCRYSTALLINE SINTERED BODY OF YTTRIUM OXIDE HAVING A HIGH IN-LINE TRANSMISSION IS OBTAINED.
Claim 4
Independent Claim
209 words
A METHOD FOR PRODUCING A TRANSPARENT HIGHLY PURE SINTERED POLYCRYSTALLINE BODY CONSISTING ESSENTIALLY OF YTTRIUM OXIDE HAVING A HIGH IN-LINE TRANSMISSION FOR A WIDE RANGE SPECTRUM FROM VISIBLE TO FAIR INFRARED RAYS, COMPRISING THE STEPS OF (1) PRESS MOLDING A MIXTURE OF HIGHLY PURE YTTRIUM OXIDE HAVING A PURITY OF AT LEAST 99.9% AND 0.01 TO 1.0% BY WEIGHT, BASED ON YTTRIUM OXIDE AND MEASURED AS BERYLLIUM OXIDE, OF BERYLLIUM OXIDE AND/OR A BERYLLIUM COMPOUND EASILY CONVERTIBLE UNDER SINTERING CONDITIONS TO BERYLLIUM OXIDE UNDER A MOLDING PRESSURE OF AT LEAST 0.3 TON PER SQUARE CENTIMETER TO FORM A MOLDED BODY OF A DESIRED SHAPE, AND (2) SUBJECTING SAID MOLDED BODY TO A SINTERING TREATMENT COMPRISING (A) HEATING THE MOLDED BODY IN A DRY HYDROGEN ATMOSPHERE HAVING A DEW POINT OF ABOUT -5*C. OR LOWER AT A TEMPERATURE 2050* TO 2250*C. FOR AT LEAST ABOUT 30 MINUTES TO THEREBY SINTER THE MOLDED BODY AND (B) REFIRING THE RESULTANT SINTERED BODY IN A HYDROGEN ATMOSPHERE HAVING A DEW POINT OF AT LEAST 0*C. AND MAINTAINED AT 1800* TO 2250*C. FOR AT LEAST ABOUT 10 MINUTES TO THEREBY EFFECT DECOLORATION OF THE SINTERED BODY, WHEREBY A HIGHLY PURE TRANSPARENT POLYCRYSTALLINE SINTERED BODY OF YTTRIUM OXIDE HAVING A HIGH IN-LINE TRANSMISSION IS OBTAINED.
Claim 5
Dependent Claim
20 words
The method according to claim 2, wherein the heating step (a) is conducted at a temperature of 2100* to 2250*C.
Claim 6
Dependent Claim
72 words
The method according to claim 2, wherein the beryllium compound is selected from the group consisting of beryllium chloride, beryllium nitrate, beryllium fluoride, beryllium sulfate, beryllium acetate and beryllium carbonate, said beryllium compound is employed instead of beryllium oxide, and the press molded body is pre-fired in air at 700* to 1200*C. for at least about 30 minutes to convert the beryllium compound to beryllium oxide prior to the sintering step (2).
Claim 7
Dependent Claim
33 words
The method according to claim 2, wherein the press molded body cOntains 0.05 to 0.5% by weight of beryllium oxide and the resultant sintered body has an in-line transmission of 70 to 81%.
Claim 8
Independent Claim
186 words
A method for producing a transparent highly pure sintered polycrystalline body consisting essentially of yttrium oxide having a high in-line transmission for a wide range spectrum from visible to far infrared rays, comprising the steps of (1) press molding highly pure yttrium oxide having a purity of at least 99.9% under a molding pressure of at least 0.3 ton per square centimeter to form a molded body of a desired shape, and (2) subjecting the molded body to a sintering treatment comprising (a) heating the molded body in a dry hydrogen atmosphere having a dew point of about -5*C. or lower and containing a vapor beryllium oxide, beryllium halides and beryllium nitrate at a temperature of 2050* to 2250*C. for at least about 30 minutes to sinter the molded body and (b) re-firing the resultant sintered body in a hydrogen atmosphere having a dew point of at least 0*C. maintained at 1800* to 2250*C. for at least about 10 minutes to effect decoloration of the sintered body, whereby a highly pure transparent polycrystalline sintered body of yttrium oxide having a high in-line transmission can be obtained.
Claim 9
Independent Claim
186 words
A method for producing a transparent highly pure sintered polycrystalline body consisting essentially of yttrium oxide having a high in-line transmission for a wide range spectrum from visible to far infrared rays, comprising the steps of (1) press molding highly pure yttrium oxide having a purity of at least 99.9% under a molding pressure of at least 0.3 ton per square centimeter to form a molded body of a desired shape, and (2) subjecting the molded body to a sintering treatment comprising (a) heating the molded body in a dry hydrogen atmosphere having a dew point of about -5*C. or lower and containing a vapor beryllium oxide, beryllium halides and beryllium nitrate at a temperature of 2050* to 2250*C. for at least about 30 minutes to sinter the molded body and (b) re-firing the resultant sintered body in a hydrogen atmosphere having a dew point of at least 0*C. maintained at 1800* to 2250*C. for at least about 10 minutes to effect decoloration of the sintered body, whereby a highly pure transparent polycrystalline sintered body of yttrium oxide having a high in-line transmission can be obtained.
Claim 10
Dependent Claim
20 words
The method according to claim 6, wherein the heating step (a) is conducted at a temperature of 2,100* to 2,250*C.
Claim 11
Independent Claim
162 words
A method for producidng a transparent highly pure sintered polycrystalline body consisting essentially of yttrium oxide having a high in-line transmission for a wide range spectrum from visible to far infrared rays, comprising the steps of (1) press molding a mixture of 99.0 to 99.99% by weight of highly pure yttrium oxide having a purity of at least 99.9% and 0.01 to 1.0% by weight, based on yttrium oxide and measured as beryllium oxide, of beryllium oxide and/or a beryllium compound easily convertible under sintering conditions to beryllium oxide under a molding pressure of at least 0.3 ton per square centimeter to form a molded body of a desired shape, and (2) sintering the molded body at a temperature of 2050* to 2250*C. for at least 30 minutes in a vacuum atmosphere in which the pressure is not higher than 10 4 Torr, whereby a highly pure transparent polycrystalline sintered body of yttrium oxide having a high in-line transmission can be obtained.
Claim 12
Independent Claim
162 words
A method for producidng a transparent highly pure sintered polycrystalline body consisting essentially of yttrium oxide having a high in-line transmission for a wide range spectrum from visible to far infrared rays, comprising the steps of (1) press molding a mixture of 99.0 to 99.99% by weight of highly pure yttrium oxide having a purity of at least 99.9% and 0.01 to 1.0% by weight, based on yttrium oxide and measured as beryllium oxide, of beryllium oxide and/or a beryllium compound easily convertible under sintering conditions to beryllium oxide under a molding pressure of at least 0.3 ton per square centimeter to form a molded body of a desired shape, and (2) sintering the molded body at a temperature of 2050* to 2250*C. for at least 30 minutes in a vacuum atmosphere in which the pressure is not higher than 10 4 Torr, whereby a highly pure transparent polycrystalline sintered body of yttrium oxide having a high in-line transmission can be obtained.
Claim 13
Dependent Claim
20 words
The method according to claim 2, wherein said molding pressure is between about 0.3 and 3 tons per square centimeter.
Claim 14
Dependent Claim
23 words
The method according to claim 2, wherein the dry hydrogen atmosphere in step (a) has a dew point of about -5* to -70*C.
Claim 15
Dependent Claim
41 words
The method according to claim 10, wherein the hydrogen atmosphere in step (b) has a dew point of about 0* to about 25*C., said re-firing being accomplished at a temperature of at least about 170*C. below the temperature in step (a).
Claim 16
Dependent Claim
28 words
The method according to claim 2, wherein step (a) is accomplished for about 30 to 300 minutes and step (b) is accomplished for about 10 to 30 minutes.
Claim 17
Dependent Claim
20 words
The method according to claim 8, wherein said molding pressure is between about 0.3 to 3 tons per square centimeter.
Claim 18
Dependent Claim
30 words
The method according to claim 8, wherein the press molded mixture of highly pure yttrium oxide is sintered at a pressure of about 10 4 Torr to 10 6 Torr.
Claim 19
Dependent Claim
26 words
The method according to claim 1, wherein the amount of beryllium oxide present is about 0.01 to 1.0% based on the weight of the yttrium oxide.
Claim 20
Independent Claim
94 words
A method for producing a transparent highly pure sintered polycrystalline body consisting essentially of yttrium oxide having a high in-line transmission for a wide range spectrum from visible to far infrAred rays, comprising the steps of (1) preparing a press molded body from highly pure yttrium oxide having a purity of at least 99.9% or a ytrrium compound convertible to yttrium oxide having a purity of at least 99.9% under sintering conditions, and (2) sintering a press molded body in an atmosphere consisting of hydrogen or a vacuum in the presence of beryllium oxide.
Claim 21
Independent Claim
94 words
A method for producing a transparent highly pure sintered polycrystalline body consisting essentially of yttrium oxide having a high in-line transmission for a wide range spectrum from visible to far infrAred rays, comprising the steps of (1) preparing a press molded body from highly pure yttrium oxide having a purity of at least 99.9% or a ytrrium compound convertible to yttrium oxide having a purity of at least 99.9% under sintering conditions, and (2) sintering a press molded body in an atmosphere consisting of hydrogen or a vacuum in the presence of beryllium oxide.
Claim 22
Dependent Claim
58 words
The method according to claim 16, wherein said press molded body is prepared by press molding a compound convertible to yttrium oxide under sintering conditions and thereafter subjecting the articles so formed to a preliminary sintering treatment conducted to 700* to 1200*C. in an oxidizing atmosphere for a time sufficient to convert said yttrium compound to yttrium oxide.
Claim 23
Dependent Claim
26 words
The method according to claim 17, wherein said yttrium compound convertible to yttrium oxide is selected from the group consisting of yttrium carbonate and yttrium oxalate.
Claim 24
Dependent Claim
72 words
The method according to claim 18, wherein 0.01 to 0.1% by weight of beryllium oxide or a compound convertible to beryllium oxide under sintering conditions are admixed with the yttrium compound convertible to yttrium oxide prior to press molding, the percents being based on the weight of said yttrium compound measured as yttrium oxide and the weight of said beryllium oxide and/or beryllium compound convertible to beryllium oxide measured as beryllium oxide.
Claim 25
Dependent Claim
109 words
The method according to claim 19, wherein said press molded body is prepared under a molding pressure of at least about 0.3 ton per square centimeter, and further wherein sintering is accomplished by (a) heating the molded body in a dry hydrogen atmosphere having a dew point of about -5*C. or lower at a temperature of 2050* to 2250*C. for at least 30 minutes to thereby sinter the molded body and (b) re-firing the resultant sintered body in a hydrogen atmosphere having a dew point of at least 0*C. and maintained at 1800* to 2250*C. for at least about 10 minutes to thereby effect decoloration of the sintered body.
Claim 26
Dependent Claim
33 words
The method according to claim 19, wherein said compound convertible to beryllium oxide is selected from the group consisting of beryllium chloride, beryllium nitrate, beryllium fluoride, beryllium sulfate, beryllium acetate and beryllium carbonate.
Claim 27
Dependent Claim
62 words
The method according to claim 19, wherein said press molded body is formed under a molding pressure of at least about 0.3 ton per square centimeter, said sintering being accomplished by heating the molded body at a temperature of about 2,050* to 2, 250*C. for at least about 30 minutes in vacuo at a pressure not higher than about 10 4 Torr.
Claim 28
Dependent Claim
49 words
The method according to claim 17, wherein said press molded body consists of yttrium oxide having a purity of at least 99.9%, said press molded body being sintered in an atmosphere containing a vapor beryllium compound selected from the group consisting of beryllium oxide, beryllium halides and beryllium nitrate.
Claim 29
Dependent Claim
108 words
The method according to claim 23, wherein the sintering treatment comprises (a) heating the press molded body in a dry hydrogen atmsophere having a dew point of about -5*C. or lower and containing a vapor of a beryllium compound selected from the group consisting of beryllium oxide, beryllium halides and beryllium nitrate at a temperature of 2,050* to 2,250*C. for at least about 30 minutes to sinter the molded body and (b) re-firing the resultant sintered body in a hydrogen atmosphere having a dew point of at least 0*C. and maintained at 1,800* to 2,250*C. for at least about 10 minutes to effect decoloration of the sintered body.
References Cited (Backward Citations)
US2805166A
Cited
US3764643A
Cited
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 |