A pillar shaped honeycomb structure includes: an outer peripheral wall; and porous partition walls disposed on an inner side of the outer peripheral wall, the partition walls defining a plurality of cells, each of the cells extending from one end face to other end face to form a flow path, wherein the cells include a plurality of wire pieces made of a magnetic substance, the wire pieces being provided apart from each other via spaces or buffer materials in an extending direction of the cells.

Disclosed is a ceramic honeycomb structure comprising a honeycomb body and a multilayered outer layer formed of a thick core layer applied and rapidly dried and a thin clad layer dried more gently to form a crack free dual skin layer. The core layer may have properties that are closer to those of the ceramic honeycomb body in service than the clad layer that may provide a tough outer shell to withstand handling and assembly.

The honeycomb structure includes a honeycomb structure body and a pair of electrode members disposed on a side surface of the honeycomb structure body, each of the pair of electrode members is shaped in the form of a band extending in a cell extending direction, and in a cross section perpendicular to the extending direction of cells, one electrode member is disposed on a side opposite to the other electrode member via a center of the honeycomb structure body, one or more slits opened in the side surface are formed in the honeycomb structure body, the honeycomb structure body has a charging material charged into the at least one slit, the charging material contains aggregates and a neck material, and a ratio (α2/α1) of a thermal expansion coefficient α2 of the charging material to a thermal expansion coefficient α1 of the honeycomb structure body is from 0.6 to 1.5.

A honeycomb structure includes honeycomb segments each having a porous partition wall defining a plurality of cells, and includes a porous bonding layer containing a crystalline anisotropic ceramic and disposed so as to bond side surfaces of the honeycomb segments to each other. A ratio of a pore volume (cc/g) of a fine pore defined as a pore in the bonding layer having a pore diameter of 10 μm or more and less than 50 μm with respect to a pore volume (cc/g) of a coarse pore defined as a pore in the bonding layer having a pore diameter of 50 μm or more and 300 μm or less is from 2.0 to 3.5, the pore volume of the fine pore is from 0.15 to 0.4 cc/g, and the pore volume of the coarse pore is from 0.05 to 0.25 cc/g.

A heat conduction member includes: a cylindrical ceramic body, a metal pipe on the outer periphery side of the cylindrical ceramic body, and an intermediate member held between the cylindrical ceramic body and the metal pipe. The cylindrical ceramic body has passages passing through from one end face to the other end face and allowing the first fluid to flow therethrough. The intermediate member is made of material having at least a part having a Young's modulus of 150 Gpa or less. The first fluid is allowed to flow through the inside of the cylindrical ceramic body while the second fluid having lower temperature than that of the first fluid is allowed to flow on the outer peripheral face side of the metal pipe to perform heat exchange between the first fluid and the second fluid.

A plugged honeycomb structure has a plurality of cells defined by partition walls to become through channels for fluid, one end of each of the predetermined cells is plugged by a plugging member, the other end of each of the residual cells is plugged by the plugging member, the partition wall is made of a cordierite component as a main component, and a value obtained by dividing Young's modulus of a plugging structure portion formed by the partition walls and the plugging member by Young's modulus of a cell structure portion formed by the partition walls is in a range of 1.05 to 2.00.

A joining material used for joining side surfaces of a plurality of silicon carbide-based honeycomb segments to each other to produce a silicon carbide-based honeycomb structure. The joining material contains from 0.1 to 50% by mass of processed powder generated in the production of the silicon carbide-based honeycomb segments and/or the silicon carbide-based honeycomb structure. The joining material has an average particle diameter D50 of from 0.5 to 60 μm.

A joining material used for joining side surfaces of a plurality of silicon carbide-based honeycomb segments to each other to produce a silicon carbide-based honeycomb structure. The joining material contains from 0.1 to 50% by mass of processed powder generated in the production of the silicon carbide-based honeycomb segments and/or the silicon carbide-based honeycomb structure. The joining material has an average particle diameter D50 of from 0.5 to 60 m.

A plugged honeycomb structure has a plurality of cells defined by partition walls to become through channels for fluid, one end of each of the predetermined cells is plugged by a plugging member, the other end of each of the residual cells is plugged by the plugging member, the partition wall is made of a cordierite component as a main component, and a value obtained by dividing Young's modulus of a plugging structure portion formed by the partition walls and the plugging member by Young's modulus of a cell structure portion formed by the partition walls is in a range of 1.05 to 2.00.

A honeycomb structure includes honeycomb segments each having a porous partition wall defining a plurality of cells, and includes a porous bonding layer containing a crystalline anisotropic ceramic and disposed so as to bond side surfaces of the honeycomb segments to each other. A ratio of a pore volume (cc/g) of a fine pore defined as a pore in the bonding layer having a pore diameter of 10 m or more and less than 50 m with respect to a pore volume (cc/g) of a coarse pore defined as a pore in the bonding layer having a pore diameter of 50 m or more and 300 m or less is from 2.0 to 3.5, the pore volume of the fine pore is from 0.15 to 0.4 cc/g, and the pore volume of the coarse pore is from 0.05 to 0.25 cc/g.