Claims
- 1. A sintered ceramic body comprising a ceramic body of at least 99% by weight titania, said body being a sintered compact treated by hot isostatic pressing; and a surface on said body having a plurality of pores therein not exceeding 100 pores per square millimeter.
- 2. A titania ceramic body consisting of
- a surface not exceeding 35 pores per square millimeter, obtainable by the process comprising:
- providing a titania powder material having a purity of not less than 99.8% by weight and an average particle diameter of not more than 0.5 microns;
- compacting said titania powder;
- sintering said compact;
- at a temperature of from 1000.degree. to 1300.degree. C. in a gas selected from the group consisting of air, an inert atmosphere and a reducing atmosphere under ordinary pressure to produce a sintered body;
- treating said sintered body by hot isostatic pressing at a temperature of from 800.degree. C. to below temperature carried out in above sintering step, in argon, under pressure of at least 500 kg/cm2; and
- grinding and polishing said treated sintered body.
- 3. The titania ceramic body in accordance with claim 2 wherein an average particle diameter of a titania powder is not more than 0.3 microns.
- 4. The titania ceramic body in accordance with claim 2 wherein said compact is formed by cold isostatic pressing.
- 5. The titania ceramic body in accordance with claim 2 wherein the sintering gas is argon.
- 6. The titania ceramic body in accordance with claim 2 wherein the pressure in the hot isostatic pressing treatment step is at least 1500 kg/cm2.
- 7. A sintered ceramic body comprising a ceramic body of at least 99.8% by weight titania, said body being a sintered compact treated by hot isostatic pressing; and a surface on said body having a plurality of pores therein not exceeding 100 pores per square millimeter.
Parent Case Info
This is a Divisional of application Ser. No. 08/554,098 filed Nov. 6, 1995, now U.S. Pat. No. 5,665,663, which in turn is a Continuation of application Ser. No. 08/087,746 filed Jul. 12, 1993, now abandoned, which in turn is a nationalization of PCT/JP92/01267 filed Oct. 1, 1992, now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (5)
Number |
Date |
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1-129904 |
May 1989 |
JPX |
3-150258 |
Jun 1991 |
JPX |
03150258 |
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4-114984 |
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Divisions (1)
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Number |
Date |
Country |
Parent |
554098 |
Nov 1995 |
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Continuations (1)
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Number |
Date |
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Parent |
87746 |
Jul 1993 |
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