There is disclosed a plugged honeycomb structure. A plugged honeycomb structure includes a pillar-shaped honeycomb structure body having porous partition walls defining a plurality of cells which become through channels for a fluid and extend from a first end face to a second end face, and plugging portions disposed in open ends of predetermined cells in the first end face and open ends of residual cells in the second end face, and the partition walls are constituted of a porous body including -Al.sub.2O.sub.3 as a main phase and further including cordierite and Y.sub.2Si.sub.2O.sub.7.

A packaging system for honeycomb assemblies, each including a honeycomb body and reinforcing tube held together by an interference fit or axial compression achieved by thermal expansion coefficient differences between the honeycomb body and reinforcing tube. The reinforcing tube then protects the honeycomb body, facilitating a compact and structurally-strong package.

A ceramic precursor composition suitable for sintering form a ceramic material or structure therefrom, for example, a ceramic honeycomb structure, a ceramic material or structure, for example, a ceramic honeycomb structure obtainable by sintering said ceramic precursor composition, a method for preparing said ceramic precursor composition and ceramic material or structure, for example, ceramic honeycomb structure, a diesel particulate filter comprising said ceramic structure, a selective diesel particulate filter comprising said ceramic structure, a gasoline particulate filter comprising said ceramic structure, a vehicle comprising said diesel particulate filter, selective diesel particulate filter or gasoline particulate filter, and a SCR catalyst system comprising said ceramic material or structure.

A ceramic honeycomb structure comprising pluralities of honeycomb segments each having pluralities of longitudinally penetrating flow paths partitioned by porous cell walls and plugs formed in the end portions of the flow paths, and a bonding material layer boding the peripheral walls of the honeycomb segments, the bonding material layer comprising silicon carbide particles as aggregate and a bonding phase bonding the silicon carbide particles, the bonding phase comprising at least a cordierite phase and a spinel phase, the molar ratio M1 of the cordierite phase [=cordierite phase/(cordierite phase+spinel phase)] being 0.50 or more and less than 1.0, and the content of (cordierite phase+spinel phase) in the bonding phase being 50% or more by mass.

An article, includes a porous ceramic honeycomb body and a housing disposed on at least one of an outer periphery of the porous ceramic honeycomb body and opposing end faces of the porous ceramic honeycomb body, wherein the housing exerts a compressive force on the porous ceramic honeycomb body in at least one of radial direction and axial direction. A method of making the article, includes heating to greater than or equal to about 200 C the housing, crimping the housing tightly around the honeycomb body while the housing is greater than or equal to about 200 C, and cooling the housing. The housing exerts a compressive force on the porous ceramic honeycomb body in at least one of radial direction and axial direction by shrinking on cooling more than the honeycomb body.

A honeycomb filter, wherein when a thermal expansion coefficient at 300 to 600 C. of a material constituting a honeycomb substrate is indicated by A (10.sup.6/ C.), the four-point bending strength of the material constituting the honeycomb substrate is indicated by B (MPa), the thickness of a thinnest portion in a portion partitioning outlet plugging cells of a partition wall 1 is indicated by t (mm), the thickness of a portion partitioning an outlet plugging cell and an inlet plugging cell of the partition wall is indicated by WT (mm), and the distance between the center of the outlet plugging cell and the center of the inlet plugging cell adjacent to each other is indicated by CP (mm), a relation of the following equation (1) is satisfied.
0.714WT+0.160t/CP0.163A/B+0.105(1)

A porous honeycomb structure including cell channels passing through an interior of the porous honeycomb structure and partitioned by porous partition walls, wherein the porous partition walls include skeleton portions containing an aggregate and a bonding material, and pore portions formed among the skeleton portions and through which a fluid can flow; and the porous partition walls have a porosity of 40 to 48% as measured by a mercury intrusion method, and a cumulative 50% pore diameter (D50) from a large pore side of 6 to 10 m in a volume-based cumulative distribution of pore diameters measured by the mercury intrusion method, and a maximum pore diameter observed with a scanning electron microscope of 40 m or less, and a ratio of a contact area between the aggregate and the bonding material to a surface area of the bonding material observed with the scanning electron microscope of 61 to 80%.

A pillar shaped honeycomb structure, including: an outer peripheral wall; and a porous partition wall disposed inside the outer peripheral wall, the a porous partition wall defining a plurality of cells, each of the cells extending from one end face to other end face to form a flow path, wherein a surface of the porous partition wall in the cells comprise a collecting layer having an average pore diameter lower than that of the porous partition wall; and wherein magnetic particles having a Curie point of 700 C. or higher are provided either or both between the surfaces of the porous partition wall and the collecting layer, and on the collecting layer.

Porous ceramic honeycomb articles for use as particulate filters and processes for making the same are described herein. The porous ceramic honeycomb articles include a fired cordierite body. The fired cordierite body has a microcrack parameter (Nb.sup.3) of about 0.05 to about 0.25 prior to exposure to a microcracking condition. After exposure to the microcracking condition, the fired cordierite body has a microcrack parameter (Nb.sup.3) at least 20% greater than the microcrack parameter prior to exposure to the microcracking condition. The fired cordierite body has a coefficient of thermal expansion (CTE) of about 7.010.sup.7/ C. to about 15.010.sup.7/ C. over from about 25 C. to about 800 C. prior to exposure to the microcracking condition and a coefficient of thermal expansion of about 1.010.sup.7/ C. to about 10.010.sup.7/ C. over from about 25 C. to about 800 C. after exposure to the microcracking condition. The microcrack parameter may include a thermal cycle or a chemical treatment.

A ceramic honeycomb filter including a ceramic honeycomb structure having large numbers of flow paths partitioned by porous cell walls, and plugs disposed in the flow paths alternately on the exhaust gas inlet or outlet side, to remove particulate matter from an exhaust gas passing through the porous cell walls; the porous cell walls having porosity of 45-75%, the median pore diameter A (m) of the cell walls measured by mercury porosimetry, and the median pore diameter B (m) of the cell walls measured by a bubble point method meeting the formula of 35<(AB)/B10070, and the maximum pore diameter of the cell walls measured by a bubble point method being 100 m or less.