Patent EP0168606A2 successfully refreshed from Google Patents.
EP0168606A2
Expired / Lapsed
EP
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Process for producing alumina bodies
Assignee: Saint Gobain Abrasives Inc
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Filing: 1985-05-31
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Granted: —
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Expires: 2005-05-31
Abstract
Abstract A method is described for producing hard, dense, finely crystalline fired bodies from alumina gels of solids content greater than 45%, by the use of high pressure in mixing and/or pressure extrusion together with seeding of the gel by submicron alpha alumina particles.
Inventors
- 👤 Ralph Bauer
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 11:16
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C09; C09K; C09K3/00; C09K3/14; C09K3/1409; C09K3/1418; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/1115
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
58 words
A method for making polycrystalline alpha alumina bodies having a submicron crystal size from dispersable alumina hydrate powders comprising mixing said powders with water, with submicron alpha alumina seed, and with acid, to a solids content of greater than 25%, exerting a pressure on the mixture, and firing the resulting body having a porosity of less than 10%.
Claim 2
Independent Claim
58 words
A method for making polycrystalline alpha alumina bodies having a submicron crystal size from dispersable alumina hydrate powders comprising mixing said powders with water, with submicron alpha alumina seed, and with acid, to a solids content of greater than 25%, exerting a pressure on the mixture, and firing the resulting body having a porosity of less than 10%.
Claim 3
Dependent Claim
19 words
A method according to claim 1, in which the alumina hydrate is hydrothermally treated prior to shaping and firing.
Claim 4
Dependent Claim
21 words
A method according to claim 1 or 2, in which pressure is applied by forcing said mixtures through an extrusion die.
Claim 5
Independent Claim
20 words
A method according to any one of the preceding claims, in which the pressure is applied during the mixing operation.
Claim 6
Independent Claim
23 words
A method according to any one of the preceding claims, in which the resulting aluminous bodies have a hardness greater than 16 GPa.
Claim 7
Independent Claim
24 words
A method according to any one of the preceding claims, in which the resulting aluminous bodies have a density greater than 97% of theoretical.
Claim 8
Independent Claim
30 words
A method according to any one of the preceding claims, wherein the seed material is present in an amount not greater than 5% by weight of the raw material solids.
References Cited (Backward Citations)
No citation records indexed.
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