Patent US5718336A successfully refreshed from Google Patents.
Patent US4895815A successfully refreshed from Google Patents.
US4895815A
Expired / Lapsed
US
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Sintered form body
Assignee: Feldmuehle AG
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Filing: 1987-12-03
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Granted: 1990-01-23
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Expires: 2007-12-03
Abstract
Abstract Disclosed is a starting mixture for the preparation of a sintered body on a basis of aluminum titanate consists of more than 46 wt.-% TiO 2 , up to 49.5 wt.-% Al 2 O 3 , 3 to 5 wt.-% quartz, and less than 0.2 wt.-% impurities, Al 2 O 3 and TiO 2 being present in the weight ratio of 1:0.95 to 1:1.05. The sintered body according to the invention is composed of: 15 to 35 wt.-% TiO 2 ; 60 to 85 wt.-% Al 2 TiO 5 (aluminum titanate); up to 5 wt.-% Al 2 O 3 ; up to 17 wt.-% Mullite; and max. 0.2 wt.-% impurities, all parts by weight together totaling 100 wt.-%. Also disclosed are processes for making the sintered body.
Inventors
- 👤 Hans Olapinski
- 👤 Wolfgang Burger
- 👤 Ulf Dworak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:29
CPC Classifications
F; F01; F01N; F01N13/00; F01N13/16; C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/478
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
74 words
A mixture for producing a sintered body on a basis of aluminum titanate, the mixture consisting essentially of: more than 46 wt.-% TiO 2 ; up to 49.5 wt.-% Al 2 O 3 ; 3 to 5 wt.-% quartz (SiO 2 ); less than 0.2 wt.-% impurities, the Al 2 O 3 and TiO 2 being present in a weight ratio of 1:0.95 to 1:1.05, and all weight parts together make up 100 weight-percent.
Claim 2
Dependent Claim
74 words
A mixture for producing a sintered body on a basis of aluminum titanate, the mixture consisting essentially of: more than 46 wt.-% TiO 2 ; up to 49.5 wt.-% Al 2 O 3 ; 3 to 5 wt.-% quartz (SiO 2 ); less than 0.2 wt.-% impurities, the Al 2 O 3 and TiO 2 being present in a weight ratio of 1:0.95 to 1:1.05, and all weight parts together make up 100 weight-percent.
Claim 3
Dependent Claim
50 words
A sintered body consisting essentially of: 15 to 35 wt.-% TiO 2 ; 60 to 85 wt.-% Al 2 TiO 5 (aluminum titanate); up to 5 wt.-% Al 2 O 3 ; max. 0.2 wt.-% impurities; and up to 17 wt.-% mullite, all weight parts together making up 100 weight-percent.
Claim 4
Dependent Claim
50 words
A sintered body consisting essentially of: 15 to 35 wt.-% TiO 2 ; 60 to 85 wt.-% Al 2 TiO 5 (aluminum titanate); up to 5 wt.-% Al 2 O 3 ; max. 0.2 wt.-% impurities; and up to 17 wt.-% mullite, all weight parts together making up 100 weight-percent.
Claim 5
Dependent Claim
16 words
The sintered body of claim 2 having a density of 3.0 to 3.6 g/cm 3 .
Claim 6
Dependent Claim
19 words
The sintered body of claim 2 having a polished structure with a homogeneous distribution of the TiO 2 phase.
Claim 7
Dependent Claim
27 words
The sintered body of claim 2 having an average thermal expansion coefficient of 1.5 to 3.0×10 -6 K -1 in the range from 400° to 800° C.
Claim 8
Dependent Claim
21 words
The sintered body of claim 2 wherein the aluminum titanate has an average grain size of about 5 to 20 microns.
Claim 9
Dependent Claim
137 words
A method of preparing the sintered body of claim 2 comprising: wet grinding to a D 50 particle size<0.5 microns a starting mixture of more than 46 wt.-% TiO 2 , up to 49.5 wt.-% Al 2 O 3 , 3 to 5 wt.-% quartz (SiO 2 ), less than 0.2 wt.-% impurities, the Al 2 O 3 and TiO 2 being present in a weight ratio of 1:0.95 to 1:1.05, all weight-parts making up 100 wt.-% to form a wet ground mixture; forming a slip from the wet ground mixture; forming a green body from the slip; drying the green body to form a dried body having a green density of at least 2.4 g/cm 3 ; and sintering the dried green body at a temperature of 1350° to 1490° C. to form the sintered body.
Claim 10
Dependent Claim
17 words
The method of claim 7 wherein the sintering is for a period of 1 to 5 hours.
Claim 11
Dependent Claim
151 words
A method of preparing the sintered body according to claim 2 comprising: wet grinding to a D 50 particle size <0.5 microns a starting mixture of more than 46 wt.-% TiO 2 , up to 49.5 wt.-% Al 2 O 3 , 3 to 5 wt.-% of quartz (SiO 2 ), less than 0.2 wt.-% impurities, the Al 2 O 3 and TiO 2 being present in a weight ratio of 1:0.95 to 1:1.05, all parts by weight making up 100 wt.-% to form a wet ground mixture; forming a slip from the wet ground mixture; adding a binding agent to the slip; spray drying the mixture to form a powder mixture; pressing the powder mixture to form a green body which has a green density of at least 2.4 g/cm 3 ; and sintering the green body at a temperature of 1350° to 1490° C. to form the sintered body.
Claim 12
Dependent Claim
17 words
The method of claim 9 wherein the sintering is for a period of 1 to 5 hours.
References Cited (Backward Citations)
DE1471518A1
Cited
US4277539A
Cited
JPS573767A
Cited
US4526824A
Cited
US4483944A
Cited
DD246977A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-22 | 1993-07-24 | 1994-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-22 | 1997-07-24 | 1998-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-22 | 2001-07-24 | 2002-01-23 | $7700.00 | Window Closed / Lapsed |