# US 10,766,820 B2 · Ceramic sintered body

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- Number: US 10,766,820 B2
- Document ID: US10766820B2
- Status: Granted
- Kind: B2
- Application number: 16/312,362
- Filed: 2017-06-19
- Published: 2019-08-01
- Granted: 2020-09-08
- Earliest claimed: 2016-06-27
- Assignees: Ngk Spark Plug Co., Ltd.
- Applicants: Ngk Spark Plug Co., Ltd.
- Inventors: Jun Moteki; Yusuke Katsu; Takeshi Mitsuoka
- Web page: https://patentgrep.com/patent/US10766820B2

## CPC

- C04B 35/117: Composites
- C04B 35/10: based on aluminium oxide
- C04B 35/44: based on aluminates
- C04B 35/6261: {Milling}
- C04B 35/62625: {Wet mixtures}
- C04B 35/62695: {Granulation or pelletising (devices for shaping artificial aggregates from ceramic mixtures B28B1/004)}
- C04B 35/64: Burning or sintering processes (C04B33/32 takes precedence {; powder metallurgy B22F})
- C09K 11/7774: {Aluminates}
- C04B 35/62605: {Treating the starting powders individually or as mixtures}
- C04B 2235/3217: Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
- C04B 2235/3222: Aluminates other than alumino-silicates, e.g. spinel (MgAl2O4)
- C04B 2235/3224: Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
- C04B 2235/3225: Yttrium oxide or oxide-forming salts thereof
- C04B 2235/3227: Lanthanum oxide or oxide-forming salts thereof
- C04B 2235/3229: Cerium oxides or oxide-forming salts thereof
- C04B 2235/3286: Gallium oxides, gallates, indium oxides, indates, thallium oxides, thallates or oxide forming salts thereof, e.g. zinc gallate
- C04B 2235/5436: micrometer sized, i.e. from 1 to 100 micron
- C04B 2235/5445: submicron sized, i.e. from 0,1 to 1 micron
- C04B 2235/602: Making the green bodies or pre-forms by moulding
- C04B 2235/604: Pressing at temperatures other than sintering temperatures
- C04B 2235/6581: Total pressure below 1 atmosphere, e.g. vacuum
- C04B 2235/762: Cubic symmetry, e.g. beta-SiC
- C04B 2235/764: Garnet structure A3B2(CO4)3
- C04B 2235/77: Density
- C04B 2235/785: Submicron sized grains, i.e. from 0,1 to 1 micron
- C04B 2235/786: Micrometer sized grains, i.e. from 1 to 100 micron
- C04B 2235/96: Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
- C04B 2235/9607: Thermal properties, e.g. thermal expansion coefficient
- C04B 2235/9646: Optical properties
- 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

The durability of a ceramic sintered body is improved, and a reduction in its light emission intensity and the occurrence of a chromaticity variation are suppressed. The ceramic sintered body contains alumina and a compound represented by M13-XM2XM35O12. The volume percent of the compound in the ceramic sintered body is from 3% to 70% inclusive. The ratio of the intensity of XRD from a complex oxide of aluminum and M2 to the intensity of XRD from the compound in the ceramic sintered body is less than 0.05. The average grain diameter of the alumina contained in the ceramic sintered body is from 0.30 (μm) to 3.00 (μm) inclusive. M1 is at least one selected from Sc, Y, and lanthanoid elements, and M2 is at least one selected from lanthanoid elements except any lanthanoid element selected for M1. M3 is at least one of Al and Ga, and X is from 0.003 to 0.500 inclusive.

## Claims

### Claim 1

A ceramic sintered body characterized by comprising:
alumina (Al2O3); and
a compound represented by M13-XM2XM35O12, wherein
the volume percent of the compound in the ceramic sintered body is from 3% to 70% inclusive;
the ratio of the intensity of X-ray diffraction from a complex oxide of aluminum (Al) and the M2 to the intensity of X-ray diffraction from the compound in the ceramic sintered body is less than 0.05;
the average grain diameter of the alumina (Al2O3) contained in the ceramic sintered body is from 0.30 (μm) to 3.00 (μm) inclusive;
the M1 is at least one selected from scandium (Sc), yttrium (Y), and lanthanoid elements;
the M2 is at least one selected from lanthanoid elements except any lanthanoid element selected for the M1;
the M3 is at least one of aluminum (Al) and gallium (Ga); and
the X is from 0.003 to 0.500 inclusive.

### Claim 2 (depends on 1)

A ceramic sintered body according to claim 1, wherein
the M1 is at least one selected from scandium (Sc), yttrium (Y), gadolinium (Gd), terbium (Tb), erbium (Er), ytterbium (Yb), and lutetium (Lu); and
the M2 is at least one selected from cerium (Ce), europium (Eu), terbium (Tb), and ytterbium (Yb) except the at least one element selected for the M1.

### Claim 3 (depends on 2)

A ceramic sintered body according to claim 2, wherein the M1 is yttrium (Y).

### Claim 4 (depends on 2)

A ceramic sintered body according to claim 2, wherein the M2 is cerium (Ce).

### Claim 5 (depends on 1)

A ceramic sintered body according claim 1, wherein the M3 is aluminum (Al).

### Claim 6 (depends on 2)

A ceramic sintered body according to claim 2, wherein the M1 is yttrium (Y), the M2 is cerium (Ce), and the M3 is aluminum (Al).