EP0190668A1
Expired / Lapsed
EP
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A process for preparing ceramic bodies
Assignee: Saint Gobain Abrasives Inc
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Filing: 1986-01-30
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Granted: —
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Expires: 2006-01-30
Abstract
Abstract A process for the production of thin, fiat, water-impervious ceramic substrates which comprises slip casting a slurry of ceramic powder, wherein the ceramic powder in such slurry has at least 90% of its particles within a size range not broader than 0.3 microns and also 98% of its particles are less than 1 micron in size; drying to give a greenware substrate; and firing to give a coherent ceramic substrate.
Inventors
- 👤 Anil K. Agarwal
- 👤 Robert A. Hay
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 17:31
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/622; C04B35/626; C04B35/63; C04B35/632; C04B35/634; C04B35/63404; C04B35/6342; C04B33/00; C04B33/28; C04B35/111; C04B35/16; C04B35/18
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
71 words
A process for the production of thin, flat, water-impervious ceramic substrates comprising slip casting a slurry of ceramic powder, drying to give a greenware substrate, and firing to give a coherent ceramic substrate, characterized in that the ceramic powder in such slurry has at least 90% of its particles within a size range not broader than 0.3 microns and also 98% of its particles are less than 1 micron in size.
Claim 2
Dependent Claim
71 words
A process for the production of thin, flat, water-impervious ceramic substrates comprising slip casting a slurry of ceramic powder, drying to give a greenware substrate, and firing to give a coherent ceramic substrate, characterized in that the ceramic powder in such slurry has at least 90% of its particles within a size range not broader than 0.3 microns and also 98% of its particles are less than 1 micron in size.
Claim 3
Dependent Claim
16 words
A process according to claim 1, characterized in that said slurry is deagglomerated before slip casting.
Claim 4
Dependent Claim
32 words
A process according to claim 1 or 2, characterized in that said firing is carried out at a temperature between 1300 and 1500°C. for a period of from 0.25 to 2 hours.
Claim 5
Dependent Claim
36 words
A process according to any one of the preceding claims, characterized in that said slurry comprises alumina particles not larger than 0.4 microns, with 90% of said particles having a size between 0.1 and 0.3 microns.
Claim 6
Dependent Claim
36 words
A process according to any one of the preceding claims, characterized in that said slurry is prepared by mixing said ceramic powder in a suitable liquid for a total mixing time of 48 hours or less.
Claim 7
Dependent Claim
49 words
A thin, flat, non-porous ceramic body, characterized in that it is at least 95% of theoretical density with a composition of at least 99.5% aluminum oxide, said ceramic having an average surface roughness of not more than 44 nm and free of surface defects resulting from grinding or polishing.
Claim 8
Dependent Claim
49 words
A thin, flat, non-porous ceramic body, characterized in that it is at least 95% of theoretical density with a composition of at least 99.5% aluminum oxide, said ceramic having an average surface roughness of not more than 44 nm and free of surface defects resulting from grinding or polishing.
Claim 9
Dependent Claim
16 words
A ceramic body according to claim 6, characterized in that it is as-fired, water-inpermeable and polycrystalline.
Claim 10
Dependent Claim
23 words
A ceramic body according to claim 6 or 7, characterized in that it has a composition of at least 99.5% by weight alpha-alumina.
Claim 11
Dependent Claim
26 words
A ceramic body according to any one of claims 6 to 8, characterized in that it has a density of at least 3.9 Mg/m 3 .
Claim 12
Dependent Claim
24 words
A ceramic body according to any one of claims 6 to 9, which has an average surface roughness of 30 nm + 2.5 nm.
References Cited (Backward Citations)
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