Method for producing aluminum titanate sintered compact

• US 7,148,168 B2
• Filed: 04/16/2003
• Issued: 12/12/2006
• Est. Priority Date: 04/26/2002
• Status: Expired

• Current Assignee: OHCERA Co. Ltd.
• Original Assignee: OHCERA Co. Ltd.
• Inventors: Fukuda, Masahiro, Takahashi, Masahide, Fukuda, Masaaki, Fukuda, Tsutomu, Yoko, Toshinobu
• Primary Examiner(s): GROUP, KARL E
• Application Number:
  US10/511,272
• Publication Number:
  US 20050181929A1
• Time in Patent Office: 1,336 Days
• Field of Search: 501/118, 501/119, 501/127, 501/128, 501/134, 501/135, 501/136
• US Class Current: 501/134
• CPC Class Codes: C04B 2235/3201 Alkali metal oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3206 Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3222 Aluminates other than alumino-silicates, e.g. spinel (MgAl2O4)
• CPC Class Codes: C04B 2235/3231 Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3236 Alkaline earth titanates
• CPC Class Codes: C04B 2235/3418 Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
• CPC Class Codes: C04B 2235/3472 Alkali metal alumino-silicates other than clay, e.g. spodumene, alkali feldspars such as albite or orthoclase, micas such as muscovite, zeolites such as natrolite
• CPC Class Codes: C04B 2235/442 Carbonates
• CPC Class Codes: C04B 2235/5445 submicron sized, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/604 Pressing at temperatures other than sintering temperatures
• CPC Class Codes: C04B 2235/6562 Heating rate
• CPC Class Codes: C04B 2235/96 Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
• CPC Class Codes: C04B 2235/9607 Thermal properties, e.g. thermal expansion coefficient
• CPC Class Codes: C04B 35/478 based on aluminium titanates
• CPC Class Codes: C04B 35/63 using additives specially adapted for forming the products , e.g.. binder binders
• CPC Class Codes: C04B 35/632 Organic additives

Abstract

The present invention provides a raw material composition for preparing a sintered body of aluminum titanate, the composition comprising (i) 100 parts by weight of a mixture comprising 40 to 50 mol % of TiO₂ and 60 to 50 mol % of Al₂O₃, (ii) 1 to 10 parts by weight of an alkali feldspar represented by the formula: (Na_xK_1−x)AlSi₃O₈ (0≦x≦1), and (iii) 1 to 10 parts by weight of at least one Mg-containing component selected from the group consisting of a Mg-containing oxide with spinel structure, MgCO₃ and MgO, and a process for preparing a sintered body of aluminum titanate comprising sintering a formed product prepared from the raw material composition at 1300 to 1700° C. According to the present invention, a sintered body of aluminum titanate having high mechanical strength and ability to be stably used at high temperatures, as well as its inherent properties of low coefficient of thermal expansion and high corrosion resistance, can be obtained.

Claims

1. A raw material composition for preparing a sintered body of aluminum titanate, the composition comprising:

(i) 100 parts by weight of a mixture comprising 40 to 50 mol % of TiO₂ and 60 to 50 mol % of Al₂O₃,

(ii) 1 to 10 parts by weight of alkali feldspar represented by the formula;

(Na_xK<sub>1−

x</sub>)AlSi₃O₈ (0≦

x≦

1), and

(iii) 1 to 10 parts by weight of at least one Mg-containing component selected from the group consisting of a Mg-containing oxide with spinel structure, MgCO₃ and MgO.

2. The raw material composition for preparing a sintered body of aluminum titanate according to claim 1, wherein the alkali feldspar has such a composition that x in the formula:

(Na_xK<sub>1−

x</sub>)AlSi₃O₈ is in the range of (0≦

x≦

1).

3. The raw material composition for preparing a sintered body of aluminum titanate according to claim 1 or 2, wherein the molar ratio of Si in the alkali feldspar to Mg in the Mg-containing component is in the range of Si:

Mg=0.9;

1 to 1.1;

1.

4. A process for preparing a sintered body of aluminum titanate, the process comprising sintering a formed product at a temperature of 1300 to 1700°

C.

the formed product being prepared from a raw material composition for preparing a sintered body of aluminum titanate comprising;

(i) 100 parts by weight of a mixture comprising 40 to 50 mol % of TiO₂ and 60 to 50 mol % of Al₂O₃,

(ii) 1 to 10 parts by weight of an alkali feldspar represented by the formula;

(Na_xK<sub>1−

x</sub>)AlSi₃O8 (0≦

x≦

1), and

(iii) 1 to 10 parts by weight of at least one Mg-containing component selected from the group consisting of a Mg-containing oxide with spinel structure, MgCO₃ and MgO.

5. A sintered alloy body of aluminum titanate which is obtainable by the process comprising sintering a formed product at a temperature of 1300 to 1700°

C.,

the formed product being prepared from a raw material composition for preparing a sintered body of aluminum titanate comprising;

(i) 100 parts by weight of a mixture comprising 40 to 50 mol % of TiO₂ and 60 top 50 mol % Al₂O₃,

(ii) 1 to 10 parts by weight of an alkali feldspar represented by the formula;

(Na_xK<sub>1−

x</sub>)AlSi₃O₈ (0≦

x≦

1), and

(iii) 1 to 10 parts by weight of at least one Mg-containing component selected from the group consisting of a Mg-containing oxide with spinel structure, MgCO₃ and MgO, and the molar ratio of Si in the alkali feldspar to Mg in the Mg-containing component being in the range of Si;

Mg=0.9;

1 to 1.1;

1.