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US5141527A
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Ceramic sintered body and method of producing it
Assignee: Treibacher Chemische Werke AG
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Filing: 1990-03-23
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Granted: 1992-08-25
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Expires: 2010-03-23
Abstract
Abstract Ceramic sintered body, in particular abrasive grain, based on α-Al 2 O 3 , said body being arranged in such a manner that improved abrasive results are achieved, said body being bound into a structure by means of a glass-like ceramic binder and showing a drop in hardness from its center to its edge of less than 1800 N/mm 2 , preferably less than 1000 N/mm 2 , and, in particular, less than 500 N/mm 2 .
Inventors
- 👤 Herwig Winkler
- 👤 Peter Janz
- 👤 Georg Gottschamel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:27
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/1115; C09; C09K; C09K3/00; C09K3/14; C09K3/1409; C09K3/1418
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
67 words
Method for producing a ceramic body based on α-Al 2 O 3 by a sintering process, wherein the ceramic body is presintered then deaerated in a vacuum and said body is subsequently treated with an aqueous suspension said suspension having solid matter with a grain size of less than 0.5 μm, whereinafter the suspension is taken away and the bodies thus treated are dried and sintered again.
Claim 2
Dependent Claim
67 words
Method for producing a ceramic body based on α-Al 2 O 3 by a sintering process, wherein the ceramic body is presintered then deaerated in a vacuum and said body is subsequently treated with an aqueous suspension said suspension having solid matter with a grain size of less than 0.5 μm, whereinafter the suspension is taken away and the bodies thus treated are dried and sintered again.
Claim 3
Dependent Claim
65 words
Method for producing a ceramic body based on α-Al 2 O 3 by a sintering process, wherein the presintered ceramic body is deaerated in a vacuum and said body is subsequently treated with an aqueous suspension said suspension having solid matter with a grain size of less than 0.05 μm, whereinafter the suspension is taken away and the bodies thus treated are dried and sintered.
Claim 4
Dependent Claim
65 words
Method for producing a ceramic body based on α-Al 2 O 3 by a sintering process, wherein the presintered ceramic body is deaerated in a vacuum and said body is subsequently treated with an aqueous suspension said suspension having solid matter with a grain size of less than 0.05 μm, whereinafter the suspension is taken away and the bodies thus treated are dried and sintered.
Claim 5
Dependent Claim
64 words
Method for producing a ceramic body based on α-Al 2 O 3 by a sintering process, wherein the presintered ceramic bodies deaerated in a vacuum and said body is subsequently treated with an aqueous suspension said suspension having solid matter with a grain size of less than 0.02 μm, whereinafter the suspension is taken away and the bodies thus treated are dried and sintered.
Claim 6
Dependent Claim
64 words
Method for producing a ceramic body based on α-Al 2 O 3 by a sintering process, wherein the presintered ceramic bodies deaerated in a vacuum and said body is subsequently treated with an aqueous suspension said suspension having solid matter with a grain size of less than 0.02 μm, whereinafter the suspension is taken away and the bodies thus treated are dried and sintered.
Claim 7
Dependent Claim
32 words
Method of claim 1 wherein the solid matter of the suspension consists of an Al-containing compound selected from the group consisting of highly disperse α-Al-oxide monohydrate, Al 2 O 3 and Al-hydroxide.
Claim 8
Dependent Claim
32 words
Method of claim 2 wherein the solid matter of the suspension consists of an Al-containing compound selected from the group consisting of highly disperse α-Al-oxide monohydrate, Al 2 O 3 and Al-hydroxide.
Claim 9
Dependent Claim
32 words
Method of claim 3 wherein the solid matter of the suspension consists of an Al-containing compound selected from the group consisting of highly disperse α-Al-oxide monohydrate, Al 2 O 3 and Al-hydroxide.
Claim 10
Dependent Claim
22 words
Method of claim 1 wherein the solid matter of the suspension is 5-30 weight percent (calculated as Al 2 O 3 ).
Claim 11
Dependent Claim
22 words
Method of claim 1 wherein the solid matter of the suspension is 10-25 weight percent (calculated as Al 2 O 3 ).
Claim 12
Dependent Claim
23 words
Method of claim 1 wherein an addition of an acid of up to 10 weight percent is made to the solid matter suspension.
Claim 13
Dependent Claim
24 words
Method in accordance with claim 9 wherein the added acid is selected from the group consisting of nitric acid, hydrochloric acid and acetic acid.
Claim 14
Dependent Claim
24 words
Method of claim 1 wherein there is a weight increase, due to the treatment with solid matter suspension, amounts to 0.5 to 10 percent.
Claim 15
Dependent Claim
24 words
Method of claim 1 wherein there is a weight increase, due to the treatment with solid matter suspension, amounts to 1 to 6 percent.
Claim 16
Dependent Claim
37 words
Method of claim 1 wherein the sintering of the bodies treated with the solid matter suspension takes place at temperatures between 1100° C. and 1400° C. during a period ranging from 15 minutes up to 4 hours.
Claim 17
Dependent Claim
37 words
Method of claim 4 wherein the sintering of the bodies treated with the solid matter suspension takes place at temperatures between 1100° C. and 1400° C. during a period ranging from 15 minutes up to 4 hours.
Claim 18
Dependent Claim
37 words
Method of claim 7 wherein the sintering of the bodies treated with the solid matter suspension takes place at temperatures between 1100° C. and 1400° C. during a period ranging from 15 minutes up to 4 hours.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-25 | 1996-02-24 | 1996-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-25 | 2000-02-24 | 2000-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-25 | 2004-02-24 | 2004-08-25 | $7700.00 | Window Closed / Lapsed |