Patent US5229339A successfully refreshed from Google Patents.
US5229339A
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Pressure casting ceramic slurries
Assignee: Saint Gobain Abrasives Inc
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Filing: 1991-11-12
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Granted: 1993-07-20
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Expires: 2011-11-12
Abstract
Abstract Aqueous suspensions of ceramic particles in which the particle are coated by a metal oxide sintering aid or metal hydroxide precursor thereto and which have a sufficiently high solids content to produce casting slips which can yield net shape castings are provided. The suspensions are produced by concentrating lower solids content suspensions by crossflow filtration which disrupts hydroxide gels which inherently form by interaction of the coating with water. The resultant highly loaded aqueous suspensions may be used in net shape casting to produce cast bodies of high dimensional stability, high green strength, and with a low incidence of cracking.
Inventors
- 👤 Vimal K. Pujari
- 👤 Craig A. Willkens
- 👤 Ajay K. Garg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:47
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/58007; C04B35/58014; C04B35/581; C04B35/583; C04B35/584; C04B35/593; C04B35/5935; C04B35/622; C04B35/626; C04B35/62605; C04B35/62625; C04B35/6263; C04B35/628; C04B35/62802; C04B35/62805; C04B35/6281; C04B35/62815; C04B35/63; C04B35/632; C04B35/634; C04B35/63404; C04B35/63416; C04B35/63424; C04B35/63448; C04B35/63488; C04B35/64; C04B35/645; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3224; C04B2235/3225; C04B2235/38; C04B2235/3852; C04B2235/386; C04B2235/3865; C04B2235/3873; C04B2235/3886; C04B2235/60; C04B2235/602; C04B2235/6027; C04B2235/608; C04B2235/70; C04B2235/96
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
75 words
A process for preparing an aqueous suspension of ceramic particles at a solids loading greater than about 65 wt%, wherein the particles have a surface coating of a metal compound selected from metal hydroxides and metal oxides, wherein the process comprises subjecting an aqueous suspension of said coated ceramic particles having a solids content of less than about 50 wt % to crossflow filtration until the solids loading is greater than about 65 wt %.
Claim 2
Dependent Claim
75 words
A process for preparing an aqueous suspension of ceramic particles at a solids loading greater than about 65 wt%, wherein the particles have a surface coating of a metal compound selected from metal hydroxides and metal oxides, wherein the process comprises subjecting an aqueous suspension of said coated ceramic particles having a solids content of less than about 50 wt % to crossflow filtration until the solids loading is greater than about 65 wt %.
Claim 3
Dependent Claim
16 words
The process of claim 1, wherein the solids loading is greater than about 70 wt %.
Claim 4
Dependent Claim
13 words
The process of claim 1, wherein the ceramic particles comprise an inorganic nitride.
Claim 5
Dependent Claim
28 words
The process of claim 3, wherein the ceramic particles comprises an inorganic nitride selected from the group consisting of silicon nitride, aluminum nitride, boron nitride, and titanium nitride.
Claim 6
Dependent Claim
12 words
The process of claim 3, wherein the ceramic particles comprise silicon nitride.
Claim 7
Dependent Claim
12 words
The process of claim 1, wherein the surface coating is substantially uniform.
Claim 8
Dependent Claim
20 words
The process of claim 1, wherein the surface coating is a sintering aid or precursor thereto for the ceramic particles.
Claim 9
Dependent Claim
35 words
The process of claim 7, wherein the sintering aid or precursor is an oxide or hydroxide of a metal selected from the group consisting essentially of yttrium, magnesium, zirconium, aluminum, cerium, hafnium, and mixtures thereof.
Claim 10
Dependent Claim
31 words
The process of claim 7, wherein the sintering aid or precursor is an oxide or hydroxide of a metal selected from the group consisting essentially of yttrium, magnesium, and mixtures thereof.
Claim 11
Dependent Claim
22 words
The process of claim 7, wherein the sintering aid comprises a compound selected from the group consisting of yttria and yttrium hydroxide.
Claim 12
Dependent Claim
16 words
The process of claim 1, wherein the coated particles comprise silicon nitride coated with yttrium hydroxide.
Claim 13
Dependent Claim
45 words
A flowable aqueous composition of coated ceramic particles as a solids content of greater than about 65 wt% wherein the ceramic particles are coated with a substantially uniform surface coating of a metal compound selected from the group consisting of metal hydroxides and metal oxides.
Claim 14
Dependent Claim
45 words
A flowable aqueous composition of coated ceramic particles as a solids content of greater than about 65 wt% wherein the ceramic particles are coated with a substantially uniform surface coating of a metal compound selected from the group consisting of metal hydroxides and metal oxides.
Claim 15
Dependent Claim
13 words
The composition of claim 12, wherein the ceramic particles comprise an inorganic nitride.
Claim 16
Dependent Claim
24 words
The composition of claim 13, wherein the nitride is selected from the group consisting of silicon nitride, aluminum nitride, boron nitride, and titanium nitride.
Claim 17
Dependent Claim
11 words
The composition of claim 13, wherein the nitride comprises silicon nitride.
Claim 18
Dependent Claim
32 words
The composition of claim 12, wherein the metal compound is selected from the group consisting of a sintering aid for ceramic particles and a precursor to a sintering aid for ceramic particles.
Claim 19
Dependent Claim
35 words
The composition of claim 16, wherein the sintering aid or precursor is an oxide or hydroxide of a metal selected from the group consisting essentially of yttrium, magnesium, zirconium, aluminum, cerium, hafnium, and mixtures thereof.
Claim 20
Dependent Claim
22 words
The composition of claim 16, wherein the sintering aid comprises a compound selected from the group consisting of yttria and yttrium hydroxide.
Claim 21
Dependent Claim
16 words
The composition of claim 12 wherein the ceramic particles comprise silicon nitride coated with yttrium hydroxide.
References Cited (Backward Citations)
US4834928A
Cited
US5047181A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1996-07-19 | 1997-01-18 | 1997-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-19 | 2001-01-18 | 2001-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-19 | 2005-01-18 | 2005-07-20 | $7700.00 | Window Closed / Lapsed |