# US 8,784,521 B2 · Bonded abrasive article and method of forming

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- Number: US 8,784,521 B2
- Document ID: US8784521B2
- Status: Granted
- Kind: B2
- Application number: 12/959,273
- Filed: 2010-12-02
- Published: 2011-06-09
- Granted: 2014-07-22
- Earliest claimed: 2009-12-02
- Assignees: Saint-Gobain Abrasives, Inc.; Saint-Gobain Abrasifs
- Applicants: Gilles Querel; Sandhya Jayaraman Rukmani; Muthu Jeevanantham; Kelley McNeal; Stephen E. Fox
- Inventors: Gilles Querel; Sandhya Jayaraman Rukmani; Muthu Jeevanantham; Kelley McNeal; Stephen E. Fox
- Web page: https://patentgrep.com/patent/US8784521B2

## CPC

- B24D 3/04: and being essentially inorganic
- C03C 3/093: containing zinc or zirconium
- C03C 14/004: {the non-glass component being in the form of particles or flakes}
- C04B 35/1115: {Minute sintered entities, e.g. sintered abrasive grains or shaped particles such as platelets (abrasives C09K3/14)}
- C04B 35/62813: {Alumina or aluminates}
- C04B 35/6316: {Binders based on silicon compounds}
- C09K 3/1409: {Abrasive particles per se (preparation of diamond C01B32/25)}
- C03C 2214/20: Glass-ceramics matrix
- C04B 2235/3217: Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
- C04B 2235/36: Glass starting materials for making ceramics, e.g. silica glass
- C04B 2235/365: Borosilicate glass
- B24D: TOOLS FOR GRINDING, BUFFING OR SHARPENING (abrading-bodies specially designed for tumbling apparatus, e.g. abrading-balls B24B31/14; honing tools B24B33/08; lapping tools B24B37/11)
- C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

An abrasive article includes an abrasive body having abrasive grains within a bond material, the abrasive body further including a spinel material disposed at an interface between the abrasive grains and the bond matrix.

## Claims

### Claim 1

An bonded abrasive article comprising:
an abrasive body including abrasive grains within a bond material comprising an amorphous phase, the abrasive body further including a passivation region comprising a spinel material, wherein the passivation region is within the bond material and surrounds a majority of the abrasive grains, wherein the abrasive grains comprise microcrystalline aluminum oxide and wherein the bond material comprises less than about 50 vol % of a crystalline phase.

### Claim 2 (depends on 1)

The bonded abrasive article of claim 1, wherein the abrasive body comprises a porosity of at least about 20 vol % and less than about 40 vol % of the total volume of the abrasive article.

### Claim 3 (depends on 1)

The bonded abrasive article of claim 1, wherein the passivation region consists essentially of a spinel material.

### Claim 4 (depends on 1)

The bonded abrasive article of claim 1, wherein the bond material comprises at least about 5.0 mol % magnesium oxide.

### Claim 5 (depends on 1)

The bonded abrasive article of claim 1, wherein the bond material consists essentially of an amorphous phase.

### Claim 6 (depends on 1)

The bonded abrasive article of claim 1, wherein the bond material comprises boron oxide (B2O3).

### Claim 7 (depends on 6)

The abrasive article of claim 6, wherein the bond material comprises between about 5 mol % and about 25 mol % boron oxide.

### Claim 8 (depends on 1)

The bonded abrasive article of claim 1, wherein the bond material comprises an alkali oxide compound selected from the group of oxide compounds consisting of lithium oxide (Li2O), potassium oxide (K2O), sodium oxide (Na2O), cesium oxide (Cs2O), and a combination thereof.

### Claim 9 (depends on 8)

The bonded abrasive article of claim 8, wherein the bond material comprises a total content of alkali oxide compounds [Caoc] within a range between about 2 mol % and about 20 mol %.

### Claim 10 (depends on 1)

The bonded abrasive article of claim 1, wherein the bond comprises an alkaline earth oxide compound selected from the group of materials consisting of magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), barium oxide (BaO), and a combination thereof.

### Claim 11 (depends on 10)

The bonded abrasive article of claim 10, wherein the bond comprises a total content of alkaline earth oxide compounds [Caeoc] within a range between about 5 mol % and about 50 mol %.

### Claim 12 (depends on 1)

The bonded abrasive article of claim 1, wherein the spinel material is represented by the general equation AB2O4, wherein A is an element selected from the group consisting of magnesium, zinc, manganese, iron, and a combination thereof, wherein B is an element selected from the group consisting of aluminum, chromium, iron, and a combination thereof, and O is oxygen.

### Claim 13

An bonded abrasive article comprising:
an abrasive body including abrasive grains contained within a matrix of bond material comprising an amorphous phase, the abrasive body further including a layer comprising a spinel material overlying an exterior surface of the abrasive grains, wherein the bond material comprises at least about 5.0 mol % magnesium oxide, wherein the abrasive grains comprise microcrystalline aluminum oxide and wherein the bond material comprises less than about 50 vol % of a crystalline phase.

### Claim 14 (depends on 13)

The bonded abrasive article of claim 13, wherein the spinel material is represented by the general equation AB2O4, wherein A is an element selected from the group consisting of magnesium, zinc, manganese, iron, and a combination thereof, wherein B is an element selected from the group consisting of aluminum, chromium, iron, and a combination thereof, and O is oxygen.

### Claim 15 (depends on 14)

The bonded abrasive article of claim 14, wherein the spinel material comprises MgAl2O4.

### Claim 16 (depends on 14)

The bonded abrasive article of claim 14, wherein the spinel material comprises a solid solution described by the composition (Mg2+, Zn2+, Fe2+, Mn2+)(Al3+)2O4.

### Claim 17 (depends on 13)

The bonded abrasive article of claim 13, wherein the bond material comprises a total content of alkali oxide compounds [Caoc] and a total content of alkaline earth oxide compounds [Caeoc], and wherein the ratio of [Caeoc]/[Caoc] has a value of less than about 1.0.

### Claim 18 (depends on 13)

The bonded abrasive article of claim 13, wherein the bond material comprises zinc oxide (ZnO).

### Claim 19

An bonded abrasive article comprising:
an abrasive body including abrasive grains contained within a matrix of bond material comprising an amorphous phase, the abrasive body further including a layer comprising a spinel material overlying an exterior surface of the abrasive grains, wherein the bond material comprises an amount of magnesium oxide that is at least about 2 times greater than an amount of any other alkaline earth oxide compound, wherein the abrasive grains comprise microcrystalline aluminum oxide and wherein the bond material comprises less than about 50 vol % of a crystalline phase.