CORDIERITE ALUMINUM MAGNESIUM TITANATE COMPOSITIONS AND CERAMIC ARTICLES COMPRISING SAME

• US 20140150389A1
• Filed: 11/30/2012
• Published: 06/05/2014
• Est. Priority Date: 11/30/2012
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Divens-Dutcher, Adriane Marie, Tepesch, Patrick David, Vileno, Elizabeth Marie
• Granted Patent: US 9,079,799 B2
• Time in Patent Office: Days
• US Class Current: 55/523
• CPC Class Codes: B01D 46/2429 of the honeycomb walls or cells
• CPC Class Codes: B01D 46/24491 Porosity
• CPC Class Codes: B01D 46/24492 Pore diameter
• CPC Class Codes: B01D 46/24494 Thermal expansion coefficient, heat capacity or thermal conductivity
• CPC Class Codes: C04B 2111/00793 as filters or diaphragms
• CPC Class Codes: C04B 2235/3206 Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3208 Calcium oxide or oxide-forming salts thereof, e.g. lime
• CPC Class Codes: C04B 2235/3213 Strontium 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 2235/3225 Yttrium oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3227 Lanthanum oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3229 Cerium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3232 Titanium oxides or titanates, e.g. rutile or anatase
• 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 glass constituents C04B2235/36
• CPC Class Codes: C04B 2235/3463 Alumino-silicates other than clay, e.g. mullite
• 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 2235/422 Carbon
• CPC Class Codes: C04B 2235/425 Graphite
• CPC Class Codes: C04B 2235/6567 : Treatment time
• CPC Class Codes: C04B 2235/77 : Density
• 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 2235/9607 : Thermal properties, e.g. thermal expansion coefficient
• CPC Class Codes: C04B 35/195 : Alkaline earth aluminosilicates, e.g. cordierite or anorthite
• CPC Class Codes: C04B 35/478 : based on aluminium titanates
• CPC Class Codes: C04B 38/0006 : Honeycomb structures from one or more corrugated sheets by winding or stacking C04B38/0083

Abstract

Disclosed are ceramic bodies comprised of composite cordierite aluminum magnesium titanate ceramic compositions and methods for the manufacture of same.

Claims

1. A ceramic article comprising a first crystalline phase comprised predominantly of a solid solution of aluminum titanate and magnesium dititanate and a second crystalline phase comprising cordierite, the article having a composition, as expressed in weight percent on an oxide basis of from 4 to 10% MgO;

from 40 to 55% Al₂O₃;

from 25 to 44% TiO₂;

from 5 to 25% SiO₂, and a sintering aid, the sintering aid comprising at least one of calcium oxide and strontium oxide.

2. The ceramic article of claim 1, wherein the sintering aid comprises a cerium oxide.

3. The ceramic article of claim 2, wherein the sintering aid further comprises at least one of a yttrium oxide and a lanthanum oxide.

4. The ceramic article of claim 1 having a composition expressed on an oxide basis of:

a(Al₂TiO₅)+b(MgTi₂O₅)+c(2MgO.2Al₂O₃.5SiO₂)+d(3Al₂O₃.2SiO₂)+e(MgO.Al₂O₃)+f(2MgO.TiO₂)+g(CaO)+h(SrO)+i(X)+j(Fe₂O₃.TiO₂)+k(TiO₂)+l(Al₂O₃), wherein X is at least one of CeO₂, Y₂O₃, and La₂O₃, and a, b, c, d, e, f, g, h, i, j, k, and l are weight fractions of each component such that (a+b+c+d+e+f+g+h+i+j+k+l)=1.00, and wherein 0.3≦

a≦

0.75, 0.075≦

b≦

0.3, 0.02≦

c≦

0.5, 0.0≦

d≦

0.4, 0.0≦

e≦

0.25, 0.0≦

f≦

0.1, 0.0≦

g≦

0.01, 0.0≦

h≦

0.02, 0.0015≦

(g+h), 0.0≦

i≦

0.05, 0.0≦

j≦

0.05, 0.0≦

k≦

0.2, and 0.0≦

l≦

0.1.

5. The ceramic article of claim 4, wherein 0.0025≦

g≦

0.0075.

6. The ceramic article of claim 4, wherein 0.005≦

h≦

0.015.

7. The ceramic article of claim 4, wherein the sintering aid further comprises a cerium oxide.

8. The ceramic article of claim 6, wherein the sintering aid further comprises at least one of yttrium oxide and a lanthanum oxide.

9. The ceramic article of claim 1, wherein the ceramic article comprises a total porosity % P greater than 40% by volume.

10. The ceramic article of claim 9, wherein the ceramic article comprises a coefficient of thermal expansion, as measured between 25-1000°

C., of less than or equal to 14×

10<sup>−

7</sup>/°

C.

11. The ceramic article of claim 1, wherein the sintering aid is present, on a weight percent oxide basis, in an amount in a range of 0.15 to 2 weight % relative to the total weight of the inorganic batch composition.

12. The ceramic article of claim 1 having a composition, as expressed in weight percent on an oxide basis:

of 5 to 10% MgO;

40 to 50% Al₂O₃;

30 to 35% TiO₂; and

10 to 20% SiO₂.

13. The ceramic article of claim 1, comprising a median pore size d₅₀ in a range of 10 μ

m to 30 μ

m.

14. The ceramic article of claim 13, comprising a median pore size d₅₀ in the range of from 15 μ

m to 25 μ

m.

15. A diesel particulate filter comprising the ceramic article of claim 1, wherein said diesel particulate filter comprises a honeycomb structure having a plurality of axially extending end-plugged inlet and outlet cells.

16. A ceramic article, comprising:

a pseudobrookite phase comprising predominately alumina, magnesia, and titania;

a second phase comprising cordierite; and

a sintering aid, comprising at least one of a calcium oxide and strontium oxide.

17. The ceramic article of claim 16, further comprising at least one of a lanthanide oxide and yttrium oxide.

18. The ceramic article of claim 17, wherein the lanthanide oxide comprises a cerium oxide.

19. The ceramic article of claim 17, wherein the sintering aid comprises cerium oxide and at least one of yttrium oxide and a lanthanum oxide.

20. A method of manufacturing a ceramic article, comprising:

providing an inorganic batch composition comprising a magnesia source, a silica source, an alumina source, a titania source, and at least one sintering aid;

mixing the inorganic batch composition together with one or more processing aid selected from the group consisting of a plasticizer, lubricant, binder, pore former, and solvent, to form a plasticized ceramic precursor batch composition;

shaping the plasticized ceramic precursor batch composition into a green body; and

firing the green body under conditions effective to convert the green body into a ceramic article comprising a pseudobrookite phase comprising predominately alumina, magnesia, and titania and a second phase comprising cordierite,

wherein the sintering aid comprises at least one of calcium oxide and strontium oxide.

21. The method of claim 20, wherein the sintering aid comprises at least one of a lanthanide oxide and yttrium oxide.

22. The method of claim 21, wherein the lanthanide oxide comprises a cerium oxide.

23. The method of claim 22, wherein the sintering aid comprises cerium oxide and at least one of yttrium oxide and a lanthanum oxide.

24. The method of claim 20, wherein at least one sintering aid is present, on a weight percent oxide basis, in an amount in a range of 0.15 to 2 weight % relative to the total weight of the inorganic batch composition.

25. The method of claim 24, wherein the plasticized ceramic precursor batch composition is shaped by extrusion.

26. The method of claim 20, wherein the firing conditions effective to convert the green body into a ceramic article comprise heating the green body at a first hold temperature in the range of 1250°

C. to 1450°

C. and maintaining the first hold temperature for a first hold time sufficient to convert the green body into a ceramic article.

27. The method of claim 26, wherein the first hold temperature is in the range of 1330°

C. to 1380°

C. and wherein the first hold time is in the range of from 2 to 24 hours.

28. The method of claim 26, wherein the firing conditions further comprise:

cooling the fired ceramic body to a second hold temperature less than the first hold temperature for a second hold time;

heating the ceramic body to a third hold temperature greater than a threshold temperature and less than the first hold temperature for a third hold time, wherein the third hold temperature is greater than the second hold temperature; and

cooling the ceramic body to room temperature (RT).

29. The method of claim 28, wherein the second hold temperature is in a range of 25°

C. to 500°

C., the second hold time is in a range of 1 hour to 48 hours, the third hold temperature is in a range of 850°

C. to 1350°

C., and the third hold time is in a range of 1 hour to 24 hours.