US4770671A
Expired / Lapsed
US
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Abrasive grits formed of ceramic containing oxides of aluminum and yttrium, method of making and using the same and products made therewith
Assignee: 3M Co
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Filing: 1985-12-30
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Granted: 1988-09-13
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Expires: 2005-12-30
Abstract
Abstract Ceramic abrasive grits comprising alpha alumina and at least about 0.5 percent by weight yttria are prepared by mixing an aqueous dispersion of alpha alumina monohydrate and yttrium compound, gelling the resultant mixture, drying the gel to produce a dried solid, crushing the dried material to produce grits, calcining the dried grits to substantially remove bound volatile materials, and firing the grits to produce a ceramic material. The yttrium for the most part is in the form of a yttrium aluminum garnet. Abrasive products comprising the abrasive grits are also claimed as is a method of grinding a workpiece with such abrasive products.
Inventors
- 👤 Larry D. Monroe
- 👤 William P. Wood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:18
CPC Classifications
C; C09; C09K; C09K3/00; C09K3/14; B; B24; B24D; B24D11/00; B24D3/00; B24D3/34; B24D3/346; C01; C01F; C01F7/00; C01F7/02; C01F7/021; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/1115; C09K3/1409; C09K3/1418
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
14 words
Ceramic abrasive grits comprising alpha alumina and at least about 0.5% by weight yttria.
Claim 2
Dependent Claim
14 words
Ceramic abrasive grits comprising alpha alumina and at least about 0.5% by weight yttria.
Claim 3
Dependent Claim
18 words
The ceramic abrasive grits of claim 1 wherein said yttria is in the form of a garnet phase.
Claim 4
Dependent Claim
21 words
The ceramic abrasive grits of claim 1 in which the yttria content is from about 1 to about 30% by weight.
Claim 5
Dependent Claim
12 words
The ceramic abrasive grits of claim 1 further including a nucleating agent.
Claim 6
Dependent Claim
11 words
The ceramic abrasive grits of claim 1 characterized by being shaped.
Claim 7
Dependent Claim
11 words
An abrasive product comprising said ceramic abrasive grits of claim 1.
Claim 8
Dependent Claim
29 words
The abrasive product of claim 6 wherein said abrasive product is a coated abrasive product comprising a backing having adhesively bonded to one side thereof said ceramic abrasive grits.
Claim 9
Dependent Claim
27 words
The abrasive product of claim 6 wherein said abrasive product is a bonded abrasive product comprising a shaped mass of said ceramic abrasive grits and binder materials.
Claim 10
Dependent Claim
18 words
The abrasive product of claim 6 wherein said shaped mass is in the form of a grinding wheel.
Claim 11
Dependent Claim
41 words
The abrasive product of claim 6 wherein said abrasive product is a lofty non-woven abrasive product comprising an open porous lofty polymer filament structure having said ceramic abrasive grits distributed throughout said structure and adhesively bonded therein by an adhesive material.
Claim 12
Dependent Claim
48 words
A coated abrasive sheet material comprising a backing having bonded to at least one side thereof abrasive grits in coarse and fine size grades with at least a portion of the coarse grits being ceramic abrasive grits comprising alpha alumina and at least about 0.5% by weight yttria.
Claim 13
Dependent Claim
48 words
A coated abrasive sheet material comprising a backing having bonded to at least one side thereof abrasive grits in coarse and fine size grades with at least a portion of the coarse grits being ceramic abrasive grits comprising alpha alumina and at least about 0.5% by weight yttria.
Claim 14
Dependent Claim
15 words
The coated abrasive sheet material of claim 11 wherein said ceramic abrasive grits are shaped.
Claim 15
Dependent Claim
17 words
The coated abrasive sheet material of claim 11 wherein said ceramic abrasive grits contain a nucleating agent.
Claim 16
Dependent Claim
20 words
The coated abrasive sheet material of claim 11 wherein substantially all of said coarse grits comprise said ceramic abrasive grits.
Claim 17
Dependent Claim
20 words
The coated abrasive sheets material of claim 11 wherein substantially all of said abrasive grits comprise said ceramic abrasive grits.
Claim 18
Dependent Claim
13 words
The coated abrasive sheet material of claim 11 further including a grinding aid.
Claim 19
Dependent Claim
16 words
The coated abrasive sheet material of claim 16 wherein said grinding aid is KBF 4 .
Claim 20
Independent Claim
82 words
A method of making ceramic abrasive grits, said method comprising the steps of: a. mixing an aqueous dispersion of alpha alumina monohydrate and yttrium compound in an amount to provide at least about 0.5% by weight yttria after firing; b. gelling the resultant mixture; c. drying the gel to produce a dried solid; d. crushing the dried material to produce grits; e. calcining the dried grits to substantially remove bound volatile materials; and f. firing the grits to produce a ceramic material.
Claim 21
Independent Claim
82 words
A method of making ceramic abrasive grits, said method comprising the steps of: a. mixing an aqueous dispersion of alpha alumina monohydrate and yttrium compound in an amount to provide at least about 0.5% by weight yttria after firing; b. gelling the resultant mixture; c. drying the gel to produce a dried solid; d. crushing the dried material to produce grits; e. calcining the dried grits to substantially remove bound volatile materials; and f. firing the grits to produce a ceramic material.
Claim 22
Dependent Claim
17 words
The method of claim 18 wherein said yttrium compound is a yttrium salt of a volatile anion.
Claim 23
Dependent Claim
14 words
The method of claim 18 further including the step of shaping the gelled material.
Claim 24
Dependent Claim
11 words
The method of claim 20 wherein the shaping is by extrusion.
Claim 25
Dependent Claim
18 words
The method of claim 18 further including the step of adding a nucleating agent to the aqueous dispersion.
Claim 26
Independent Claim
50 words
A method of grinding a workpiece surface comprising: a. causing rapid surface movement of an abrasive article comprised of ceramic abrasive grits comprising alpha alumina and at least about 0.5% by weight yttria; and b. moving the surface of said abrasive article into surface grinding contact with said workpiece surface.
Claim 27
Independent Claim
50 words
A method of grinding a workpiece surface comprising: a. causing rapid surface movement of an abrasive article comprised of ceramic abrasive grits comprising alpha alumina and at least about 0.5% by weight yttria; and b. moving the surface of said abrasive article into surface grinding contact with said workpiece surface.
Claim 28
Dependent Claim
13 words
The method of claim 23 wherein said workpiece is made of stainless steel.
Claim 29
Dependent Claim
14 words
The method of claim 23 wherein said abrasive article also includes a grinding aid.
Claim 30
Dependent Claim
13 words
The method of claim 25 wherein said grinding aid is KBF 4 .
Claim 31
Dependent Claim
15 words
The method of claim 23 wherein said abrasive product is a coated abrasive sheet material.
Claim 32
Dependent Claim
19 words
The method of claim 27 wherein said coated abrasive sheet material is in the form of a rotatable disc.
Claim 33
Dependent Claim
42 words
The method of claim 27 wherein said coated abrasive comprises a backing having bonded to at least one side thereof abrasive grits in coarse and fine size grades with at least a portion of the coarse grits being said ceramic abrasive grits.
Claim 34
Dependent Claim
17 words
The method of claim 29 wherein substantially all of said coarse grits comprise said ceramic abrasive grits.
Claim 35
Dependent Claim
16 words
The method of claim 29 wherein substantially all of said grits comprise said ceramic abrasive grits.
Claim 36
Dependent Claim
12 words
The ceramic abrasive grits of claim 1 also including a modifying additive.
Claim 37
Dependent Claim
34 words
The ceramic abrasive grits of claim 32 wherein said modifying additive is an oxide of a metal selected from the group consisting of magnesium, zinc, cobalt, nickel, zirconium, hafnium, chromium, titanium and mixtures thereof.
Claim 38
Dependent Claim
18 words
The ceramic abrasive grits of claim 32 wherein said modifying additive forms a spinel crystal structure with alumina.
Claim 39
Dependent Claim
14 words
The ceramic abrasive grits of claim 34 wherein said spinel crystal structure comprises magnesia-alumina.
Claim 40
Dependent Claim
11 words
An abrasive article comprising the ceramic abrasive grits of claim 32.
Claim 41
Dependent Claim
21 words
The method of claim 18 further including the step of adding a precursor of a modifying additive to the aqueous dispersion.
Claim 42
Dependent Claim
16 words
The method of claim 37 wherein said precursor comprises Mg(NO 3 ) 2 .6H 2 O.
Claim 43
Dependent Claim
23 words
Abrasive grits comprising ceramic produced by a sol-gel process, said ceramic comprising alpha alumina and at least about 0.5 percent by weight yttria.
Claim 44
Dependent Claim
23 words
Abrasive grits comprising ceramic produced by a sol-gel process, said ceramic comprising alpha alumina and at least about 0.5 percent by weight yttria.
Claim 45
Dependent Claim
39 words
Abrasive grits comprising ceramic material having a crystalline structure comprising inclusions which have a high alpha alumina content and a low yttrium-aluminum-garnet content surrounded by a zone having a higher yttrium-aluminum garnet content and a lower alpha alumina content.
Claim 46
Dependent Claim
39 words
Abrasive grits comprising ceramic material having a crystalline structure comprising inclusions which have a high alpha alumina content and a low yttrium-aluminum-garnet content surrounded by a zone having a higher yttrium-aluminum garnet content and a lower alpha alumina content.
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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) | 1991-09-13 | 1992-03-14 | 1992-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-13 | 1996-03-14 | 1996-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-13 | 2000-03-14 | 2000-09-13 | $7700.00 | Window Closed / Lapsed |