# US 2010/0167907 A1 · Method for manufacturing transparent polycrystalline aluminum oxynitride

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- Number: US 2010/0167907 A1
- Document ID: US20100167907A1
- Status: Published application
- Kind: A1
- Application number: 12/311,812
- Filed: 2006-10-16
- Published: 2010-07-01
- Earliest claimed: 2006-10-16
- Assignees: Industry-Academic Cooperation Foundation, Yeungnam University
- Inventors: Jae Hyung Lee; Bon Kyung Koo; Kyo Hun Koo; Kook Rim Lee
- Web page: https://patentgrep.com/patent/US20100167907A1

## CPC

- C04B 35/10: based on aluminium oxide
- C04B 35/111: Fine ceramics
- C04B 35/115: Translucent or transparent products
- 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

## Abstract

The present invention relates to a method of manufacturing a transparent polycrystalline aluminum oxynitride. Aluminum oxynitride manufactured by prior art methods has a great number of porosities therein and thus has low transparency. The present invention is directed to solving such a problem. In the method of manufacturing aluminum oxynitride of the present invention, a sintering additive added to a source powder includes less than 0.5 wt. % MgO. Further, the source powder is presintered at 1550° C. to 1750° C. so that a relative density becomes 95% or more and is then resintered at 1900° C. or more so that a relative density higher than that of presintering can be accomplished. According to the present invention, a cubic-phased polycrystalline aluminum oxynitride ceramic can be obtained, wherein porosities therein are nearly eliminated and its substantial transparency becomes 95% or more.

## Claims

### Claim at position 1

1-10. (canceled)

### Claim 11

A method of manufacturing a transparent polycrystalline aluminum oxynitride ceramic, comprising:
combining a source powder and a sintering additive, wherein the sintering additive includes less than 0.5% by weight of MgO.

### Claim 12 (depends on 11)

The method of claim 11, wherein the sintering additive further includes less than or equal to 0.5% by weight of Y2O3.

### Claim 13 (depends on 12)

The method of claim 12, wherein the sintering additive includes between 0.05% by weight and 0.3% by weight of MgO.

### Claim 14

A method of manufacturing a transparent polycrystalline aluminum oxynitride ceramic, comprising:
presintering a mixture comprising a source powder and a sintering additive at a temperature from 1550° C. to 1750° C. to produce a sintered product having a relative density of 95% or more; and
resintering the sintered product at a temperature of 1900° C. or more to produce a resintered product having a relative density higher than that of the sintered product.

### Claim 15

A method of manufacturing a transparent polycrystalline aluminum oxynitride ceramic comprising:
combining a source powder and a sintering additive that includes less than 0.5% by weight of MgO;
presintering the source powder at a temperature of 1550° C. to 1750° C. to produce a sintered product having a relative density of 95% or more; and
resintering the sintered product at a temperature of 1900° C. or more to produce a resintered product having a relative density higher than that of the sintered product.

### Claim 16 (depends on 15)

The method of claim 15, wherein the source powder is a mixture comprising Al2O3 and AlN powder.

### Claim 17 (depends on 16)

The method of claim 16, wherein the sintering additive comprises a mixture of 0.08% by weight of Y2O3, 0.02% by weight of BN, and 0.1% by weight of MgO.

### Claim 18 (depends on 17)

The method of claim 17, wherein presintering is performed for 10 hours at 1675° C. under a nitrogen gas atmosphere, and
wherein resintering is performed for 5 hours at 2000° C. under a nitrogen gas atmosphere.

### Claim 19 (depends on 15)

The method of claim 15, wherein the sintering additive further includes less than or equal to 0.5% by weight of Y2O3.

### Claim 20 (depends on 15)

The method of claim 15, wherein the sintering additive includes between 0.05% by weight and 0.3% by weight of MgO.