US4623364A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Abrasive material and method for preparing the same
Assignee: Saint Gobain Abrasives Inc
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Filing: 1984-10-19
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Granted: 1986-11-18
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Expires: 2004-10-19
Abstract
Abstract The hardness and microstructure of aluminous abrasives produced from alumina gels are enhanced by introduction of seed material as by wet vibratory milling of the material with alumina media, or by the direct addition of very fine alpha alumina particles in the amount of 1% or less.
Inventors
- 👤 Thomas E. Cottringer
- 👤 Ronald H. van de Merwe
- 👤 Ralph Bauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:01
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/44; C01F7/441; C01F7/442; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/1115; C09; C09K; C09K3/00; C09K3/14; C09K3/1409; C01P; C01P2004/00; C01P2004/60; C01P2004/62
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
79 words
A method of making ceramic bodies containing alpha alumina having a hardness of greater than 16 GPa, a density greater than 90%, and an alpha alumina particle size below one micron comprising providing a dispersion of submicron hydrated alumina particles, said dispersion including an effective amount of submicron alpha alumina crystals, whereby upon drying and firing said hydrated alumina particles are converted to alpha alumina at a temperature below 1100° C., and firing said body to below 1500° C.
Claim 2
Independent Claim
79 words
A method of making ceramic bodies containing alpha alumina having a hardness of greater than 16 GPa, a density greater than 90%, and an alpha alumina particle size below one micron comprising providing a dispersion of submicron hydrated alumina particles, said dispersion including an effective amount of submicron alpha alumina crystals, whereby upon drying and firing said hydrated alumina particles are converted to alpha alumina at a temperature below 1100° C., and firing said body to below 1500° C.
Claim 3
Independent Claim
70 words
A method of making an aluminous abrasive body comprising providing a dispersion of non-alpha alumina particles of submicron size, said dispersion including submicron alpha alumina seed particles, drying said dispersion and firing said dispersion whereby the non-alpha alumina particles are converted to alpha alumina particles of a submicron size and whereby said body has a density of at least 90% of theoretical and a hardness of at least 16 GPa.
Claim 4
Independent Claim
70 words
A method of making an aluminous abrasive body comprising providing a dispersion of non-alpha alumina particles of submicron size, said dispersion including submicron alpha alumina seed particles, drying said dispersion and firing said dispersion whereby the non-alpha alumina particles are converted to alpha alumina particles of a submicron size and whereby said body has a density of at least 90% of theoretical and a hardness of at least 16 GPa.
Claim 5
Independent Claim
63 words
A method of producing a polycrystalline alumina body by providing fine alumina particles in a form having a theoretical density less than that of alpha alumina, mixing submicron alpha alumina seed material with said fine alumina particles, and firing to a temperature of at least 1090° C. whereby the fine alumina particles are converted to alpha alumina crystals no coarser than 0.4 microns.
Claim 6
Independent Claim
63 words
A method of producing a polycrystalline alumina body by providing fine alumina particles in a form having a theoretical density less than that of alpha alumina, mixing submicron alpha alumina seed material with said fine alumina particles, and firing to a temperature of at least 1090° C. whereby the fine alumina particles are converted to alpha alumina crystals no coarser than 0.4 microns.
References Cited (Backward Citations)
US2947056A
Cited
US2979414A
Cited
US3079243A
Cited
US3108888A
Cited
US3121623A
Cited
US3141747A
Cited
US3216794A
Cited
US3437468A
Cited
US3615306A
Cited
US3615308A
Cited
US3940276A
Cited
US4217113A
Cited
US4252544A
Cited
US4325710A
Cited
US4314827A
Cited
GB2099012A
Cited
US4477427A
Cited
US4487756A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-11-17 | 1990-05-19 | 1990-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-17 | 1994-05-19 | 1994-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-17 | 1998-05-19 | 1998-11-18 | $7700.00 | Window Closed / Lapsed |