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US5075267A
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Light transmitting yttria sintered body and its preparation
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1990-03-02
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Granted: 1991-12-24
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Expires: 2010-03-02
Abstract
Abstract A light transmitting yttria sintered body having good light transmission, can be prepared by a method of preparing a light transmitting yttria sintered body which comprises steps of densifying yttria powder having purity of not lower than 99.9% and a BET specific surface area of not smaller than 10 m 2 /g by a hot press at a temperature of 1300° to 1700° C. under a pressure of 100 to 500 kg/cm 2 in a vacuum circumstance so as to achieve the theoretical density ratio of not lower than 95% and then hot isotropically pressing densified yttria at a temperature of 1400° to 1900° C. under a pressure of not lower than 500 kg/cm 2 .
Inventors
- 👤 Akihito Fujii
- 👤 Kenichiro Shibata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:07
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/64; C04B35/645; C04B35/6455; C04B35/50; C04B35/505
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
95 words
A light transmitting yttria sintered body which comprises a polycrystalline yttria sintered body having purity of not lower than 99.9%, said body having a grain size of not larger than 30 μm, and wherein said body has a straight transmission of not lower than 75% on the average with the visible and near infrared light having a wavelength of 0.4 to 3 μm and a straight transmission of not lower than 80% with the medium infrared light having a wavelength of 3 to 6 μm when a yttria sample has a thickness of 3 mm.
Claim 2
Dependent Claim
95 words
A light transmitting yttria sintered body which comprises a polycrystalline yttria sintered body having purity of not lower than 99.9%, said body having a grain size of not larger than 30 μm, and wherein said body has a straight transmission of not lower than 75% on the average with the visible and near infrared light having a wavelength of 0.4 to 3 μm and a straight transmission of not lower than 80% with the medium infrared light having a wavelength of 3 to 6 μm when a yttria sample has a thickness of 3 mm.
Claim 3
Independent Claim
140 words
A method of preparing a light transmitting yttria sintered body from yttria powder which possesses a purity of greater than 99.9% and a BET specific surface are of 10 m 2 /g, said method comprising the following steps: (a) subjecting said yttria powder to a densifying treatment by a hot press comprising heating the yttria to a temperature of 1300° to 1700° C. under a pressure of 100 to 500 kg/cm 2 in the presence of a vacuum; wherein the yttria sintered body formed by said hot pressing process provides a yttria body with a theoretical density ratio of not lower than 95% ; and (b) treating said formed yttria body by providing a further densification treatment of hot isotropic pressing at a temperature of 1400° to 1900° C. under a pressure of not lower than 500 kg/cm 2 .
Claim 4
Independent Claim
140 words
A method of preparing a light transmitting yttria sintered body from yttria powder which possesses a purity of greater than 99.9% and a BET specific surface are of 10 m 2 /g, said method comprising the following steps: (a) subjecting said yttria powder to a densifying treatment by a hot press comprising heating the yttria to a temperature of 1300° to 1700° C. under a pressure of 100 to 500 kg/cm 2 in the presence of a vacuum; wherein the yttria sintered body formed by said hot pressing process provides a yttria body with a theoretical density ratio of not lower than 95% ; and (b) treating said formed yttria body by providing a further densification treatment of hot isotropic pressing at a temperature of 1400° to 1900° C. under a pressure of not lower than 500 kg/cm 2 .
Claim 5
Dependent Claim
197 words
A light transmitting yttria sintered body which possesses a purity of not lower than 99.9%, a grain size of no larger than 30 μm, and has a straight transmission of not lower than 75% on the average for visible and near infrared light having a wavelength of 0.4 to 3 μm and a straight transmission of not lower than 80% with the medium infrared light having a wavelength of 3 to 6 μm when the yttria body possesses a thickness of 3 mm; wherein said yttria body is formed by the process which comprises the following steps; (a) subjecting said yttria powder to a densifying treatment by a hot press comprising heating the yttria to a temperature of 1300° to 1700° C. under a pressure of 100 to 500 kg/cm 2 in the presence of a vacuum; wherein the yttria sintered body formed by said hot pressing process provides a yttria body with a theoretical density ratio of not lower than 95%; and (b) treating said formed yttria body by providing a further densification treatment of hot isotropic pressing at a temperature of 1400° to 1900° C. under pressure of not lower than 500 kg/cm 2 .
Claim 6
Dependent Claim
197 words
A light transmitting yttria sintered body which possesses a purity of not lower than 99.9%, a grain size of no larger than 30 μm, and has a straight transmission of not lower than 75% on the average for visible and near infrared light having a wavelength of 0.4 to 3 μm and a straight transmission of not lower than 80% with the medium infrared light having a wavelength of 3 to 6 μm when the yttria body possesses a thickness of 3 mm; wherein said yttria body is formed by the process which comprises the following steps; (a) subjecting said yttria powder to a densifying treatment by a hot press comprising heating the yttria to a temperature of 1300° to 1700° C. under a pressure of 100 to 500 kg/cm 2 in the presence of a vacuum; wherein the yttria sintered body formed by said hot pressing process provides a yttria body with a theoretical density ratio of not lower than 95%; and (b) treating said formed yttria body by providing a further densification treatment of hot isotropic pressing at a temperature of 1400° to 1900° C. under pressure of not lower than 500 kg/cm 2 .
Claim 7
Dependent Claim
35 words
The method according to claim 1, wherein at least one gas selected from the group consisting of an inert gas, a nitrogen gas and an oxygen gas is used in the hot isotropic pressing treatment.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-12-23 | 1995-06-24 | 1995-12-24 | $2000.00 | Window Closed / Lapsed |
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