CORDIERITE ALUMINUM MAGNESIUM TITANATE COMPOSITIONS AND CERAMIC ARTICLES COMPRISING SAME

• US 20130210608A1
• Filed: 08/14/2012
• Published: 08/15/2013
• Est. Priority Date: 06/30/2006
• Status: Active Grant

• Current Assignee: Gregory Albert Merkel, Patrick David Tepesch, Raja Rao Wusirika
• Original Assignee: Gregory Albert Merkel, Patrick David Tepesch, Raja Rao Wusirika
• Inventors: Merkel, Gregory Albert, Tepesch, Patrick David, Wusirika, Raja Rao
• Granted Patent: US 8,673,045 B2
• Time in Patent Office: Days
• US Class Current: 501/136
• CPC Class Codes: B01D 2279/30 for treatment of exhaust gases from IC Engines
• CPC Class Codes: B01D 46/2418 Honeycomb filters used for filtering exhaust gases of an internal combustion engine F01N3/022; ceramic honeycomb structures per se C04B38/0006
• 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: B01J 35/56 Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
• CPC Class Codes: C04B 2111/00793 as filters or diaphragms
• CPC Class Codes: C04B 2111/0081 as catalysts or catalyst carriers
• CPC Class Codes: C04B 2111/2084 Thermal shock resistance
• CPC Class Codes: C04B 2111/32 Expansion-inhibited materials
• 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 2235/3225 Yttrium oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3227 Lanthanum oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3232 Titanium oxides or titanates, e.g. rutile or anatase
• 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 glass constituents C04B2235/36
• CPC Class Codes: C04B 2235/3445 : Magnesium silicates, e.g. forsterite
• 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 2235/656 : characterised by specific heating conditions during heat treatment
• CPC Class Codes: C04B 2235/6562 : Heating rate
• 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 35/195 : Alkaline earth aluminosilicates, e.g. cordierite or anorthite
• 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 38/0006 : Honeycomb structures from one or more corrugated sheets by winding or stacking C04B38/0083
• CPC Class Codes: C04B 38/0054 : the pores being microsized or nanosized
• CPC Class Codes: C04B 38/0074 : expressed as porosity percentage
• CPC Class Codes: C04B 38/0645 : Burnable, meltable, sublimable materials
• CPC Class Codes: C04B 38/068 : Carbonaceous materials, e.g. coal, carbon, graphite, hydrocarbons
• CPC Class Codes: F01N 3/0222 : the structure being monolithic, e.g. honeycombs
• CPC Class Codes: Y10T 428/24149 : Honeycomb-like

Abstract

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

Claims

1-20. -20. (canceled)

21. 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 35% TiO₂;

from 5 to 25% SiO₂, and a metal oxide sintering aid, wherein the ceramic article comprises a total porosity % P greater than 40% by volume and a coefficient of thermal expansion, as measured between 25-1000°

C., of less than or equal to 15×

10<sup>−

7</sup>/°

C.

22. The ceramic article of claim 21, wherein the metal oxide sintering aid comprises at least one of a yttrium oxide and a lanthanide oxide.

23. The ceramic article of claim 21 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(X)+i(Fe₂O₃.TiO₂)+j(TiO₂), wherein a, b, c, d, e, f, g, i, and j are weight fractions of each component such that (a+b+c+d+e+f+g+i+j)=1.00, wherein X is a metal oxide sintering aid, 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,

0.001≦

g≦

0.05,

0.0≦

i≦

0.05, and

0.0≦

j≦

0.2.

24. The ceramic article of claim 23, wherein the metal oxide sintering aid comprises at least one of a yttrium oxide and a lanthanide oxide.

25. The ceramic article of claim 21 having a composition, as expressed in weight percent on an oxide basis:

of from 5 to 10% MgO;

from 40 to 50% Al₂O₃;

from 30 to 35% TiO₂; and

from 10 to 20% SiO₂.

26. The ceramic article of claim 21, wherein the metal oxide is present, on a weight percent oxide basis, in an amount in the range of from greater than 0.1 to 5 weight % relative to the total weight of the inorganic batch composition.

27. 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 35% TiO₂;

from 5 to 25% SiO₂, and at least one metal oxide sintering aid, wherein the ceramic article comprises a total porosity % P greater than 40% by volume.

28. The ceramic article of claim 27, wherein the ceramic article comprises a coefficient of thermal expansion, as measured between 25-1000°

C., of less than or equal to 15×

10<sup>−

7</sup>/°

C.

29. The ceramic article of claim 27, wherein the ceramic article comprises a total porosity % P at least 50% by volume.

30. The ceramic article of claim 27, wherein the metal oxide sintering aid comprises at least one of a yttrium oxide and a lanthanide oxide.