Isolated pseudobrookite phase composites and methods of making

• US 9,416,056 B2
• Filed: 05/05/2015
• Issued: 08/16/2016
• Est. Priority Date: 05/30/2014
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Zimmermann, James William
• Primary Examiner(s): WIESE, NOAH S
• Application Number:
  US14/704,165
• Publication Number:
  US 20150344373A1
• Time in Patent Office: 469 Days
• Field of Search: 428/116, 428/304.4, 264/630, 264/631
• US Class Current: 1/1
• CPC Class Codes: C04B 2235/3206 Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3213 Strontium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3222 Aluminates other than alumino-silicates, e.g. spinel (MgAl2O4)
• CPC Class Codes: C04B 2235/3234 Titanates, not containing zirconia
• CPC Class Codes: C04B 2235/3236 Alkaline earth titanates
• CPC Class Codes: C04B 2235/3272 Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite
• 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 2235/3481 Alkaline earth metal alumino-silicates other than clay, e.g. cordierite, beryl, micas such as margarite, plagioclase feldspars such as anorthite, zeolites such as chabazite
• CPC Class Codes: C04B 2235/349 Clays, e.g. bentonites, smectites such as montmorillonite, vermiculites or kaolines, e.g. illite, talc or sepiolite
• CPC Class Codes: C04B 2235/36 Glass starting materials for making ceramics, e.g. silica glass
• CPC Class Codes: C04B 2235/5436 micrometer sized, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/5472 Bimodal, multi-modal or multi-fraction
• CPC Class Codes: C04B 2235/6567 Treatment time
• CPC Class Codes: C04B 2235/76 Crystal structural characteristics, e.g. symmetry
• CPC Class Codes: C04B 2235/78 Grain sizes and shapes, product microstructures, e.g. acicular grains, equiaxed grains, platelet-structures
• CPC Class Codes: C04B 2235/80 Phases present in the sintered or melt-cast ceramic products other than the main phase
• CPC Class Codes: C04B 2235/85 Intergranular or grain boundary phases
• CPC Class Codes: C04B 2235/9607 Thermal properties, e.g. thermal expansion coefficient
• CPC Class Codes: C04B 35/465 based on alkaline earth metal titanates
• CPC Class Codes: C04B 35/478 based on aluminium titanates
• CPC Class Codes: C04B 35/64 : Burning or sintering processes C04B33/32 takes precedence ; powder metallurgy B22F
• CPC Class Codes: C04B 35/66 : Monolithic refractories or refractory mortars, including those whether or not containing clay making or repairing of linings F27D1/16

Abstract

A sintered refractory ceramic composition including:

• • a pseudobrookite structured discrete first phase; and
  • a continuous second phase, as defined herein.
    Also disclosed is a method of making the sintered refractory ceramic composition.

Claims

1. A sintered refractory ceramic composition comprising:

a pseudobrookite structured discrete first phase; and

a continuous second phase,

wherein the pseudobrookite structured discrete first phase comprises from about 50 to 90 wt %, and the continuous second phase comprises from about 10 to 50 wt %, based on the total weight of the composition.

2. The composition of claim 1 wherein the sintered refractory ceramic composition comprises an aluminum-magnesium-titanium oxide ceramic.

3. The composition of claim 1 wherein the pseudobrookite structured discrete first phase comprises aluminum-magnesium-titanium oxide, and the continuous second phase comprises at least one of:

cordierite, spinel, strontium calcium aluminum silicon oxide, an amorphous phase, or a mixture thereof.

4. The composition of claim 1 wherein the pseudobrookite structured discrete first phase, the continuous phase, or both, has microcracks, is free of microcracks, one phase has microcracks and the other phase is free of microcracks, or a combination thereof.

5. The composition of claim 1 wherein the continuous second phase comprises from about 10 to 50 wt % cordierite based on the total weight of the composition.

6. The composition of claim 1 wherein the pseudobrookite structured discrete first phase includes a dopant selected from an iron source in from 0.05 mol % to 2 mol %, a silicon source in from 0.01 mol % to 2 mol %, or a combination thereof.

7. The composition of claim 6 wherein the iron source is of the formula Fe₃O₄ or FeO.Fe₂O₃, and the silicon source is silicon dioxide.

8. The composition of claim 1 wherein the composition has a high thermal insulation property of from 1.5 to 2.5 W/(m*K), and a high thermal shock property of from 700 to 800°

C.

9. A method of making the sintered refractory ceramic composition of claim 1, comprising:

forming a batch mixture comprising;

a refractory source material that when fired forms the discrete first phase, and a filler material that when fired forms the continuous second phase, the filler material having a particle size smaller than the refractory source materials and the filler material having a volume fraction of the mixture that is sufficient to encapsulate the refractory source material; and

firing the batch mixture at from 1200 to 1500°

C. for from 5 to 20 hours to form the sintered refractory ceramic composition.

10. The method of claim 9 further comprising adding a dopant in an amount of from 0.01 to 3 wt % based on the total weight of the batch to the batch mixture, the dopant being selected from at least one compound having atoms of:

silicon, iron, lithium, sodium, potassium, calcium, boron, phosphorous, silver, copper, or a combination thereof.

11. The method of claim 9 wherein the fired refractory ceramic composition comprises a pseudobrookite structured discrete first phase, and the continuous second phase encapsulates the discrete first phase.

12. The method of claim 9 wherein the discrete first phase contains from one to four phases in a solid solution, and the solid solution comprises at least one source of magnesium atoms, aluminum atoms, titanium atoms, or a mixture thereof.

13. The method of claim 9 wherein the sintered refractory ceramic composition has a chemical potential sufficient to absorb magnesium atoms, aluminum atoms, silicon atoms, or a mixture thereof, from the refractory source material, to form a continuous second phase around the resulting pseudobrookite structured discrete first phase.

14. The method of claim 9 wherein the refractory source material has a particle size having 95% of the particle diameters less than 20 micrometers, and 90% of the particle diameters are greater than 1.4 micrometers.

15. The method of claim 9 wherein the refractory source material has a particle size having 95% of the particle diameters less than 51 micrometers, and 90% of the particle diameters are greater than 5.8 micrometers.

16. The method of claim 9 wherein the filler material has a particle size having 90% of the particle diameters less than 14 micrometers, and 90% of the particle diameters are greater than 3 micrometers.

17. The method of claim 9 wherein the filler material is selected from at least one of a talc, a strontium calcium aluminum silicon oxide, or a mixture thereof.

18. The method of claim 9 wherein the filler material sieves through a 325 mesh screen.