A method for producing a honeycomb structure, the method comprising the steps of: kneading a forming raw material containing a cordierite forming material and then forming it to produce a honeycomb formed body; and firing the honeycomb formed body to provide a honeycomb structure. In the producing method, from 0.1 to 6.0 parts by mass of a magnesium silicate mineral having a 2:1 ribbon type structure per 100 parts by mass of the cordierite forming material is added to the forming raw material.

A method for manufacturing a honeycomb structure, includes: a step of manufacturing a honeycomb formed body to manufacture a non-fired honeycomb formed body having volume of 7 L or more; a drying step of drying the manufactured non-fired honeycomb formed body to obtain a honeycomb dried body; and a firing step of firing the obtained honeycomb dried body to obtain a honeycomb structure. The drying step includes: an induction drying step to obtain a first dried honeycomb formed body by removing 20 to 80% of the entire water that the non-fired honeycomb formed body contained before drying, and a microwave drying step to obtain a honeycomb dried body by removing the residual water. The honeycomb dried body subjected to this microwave drying step is obtained by removing 90% or more of the entire water that the non-fired honeycomb formed body contained before drying.

A method for manufacturing a honeycomb structure, includes: a step of manufacturing a honeycomb formed body to manufacture a non-fired honeycomb formed body having volume of 7 L or more; a drying step of drying the manufactured non-fired honeycomb formed body to obtain a honeycomb dried body; and a firing step of firing the obtained honeycomb dried body to obtain a honeycomb structure. The drying step includes: an induction drying step to obtain a first dried honeycomb formed body by removing 20 to 80% of the entire water that the non-fired honeycomb formed body contained before drying, and a microwave drying step to obtain a honeycomb dried body by removing the residual water. The honeycomb dried body subjected to this microwave drying step is obtained by removing 90% or more of the entire water that the non-fired honeycomb formed body contained before drying.

It is demanded that a LTCC substrate composition capable of maintaining low relative permittivity k and high Q value without having a reactivity with a silver which is an electrode material and causing migration of the silver during a co-firing operation at a low temperature. Provided with a low temperature co-fired substrate composition containing 83 to 91 wt. % of CaO-B.sub.2O.sub.3-SiO.sub.2 based glass powder, 7.5 to 14 wt. % of two or more kinds of nanometer-sized SiO.sub.2 powders having different ranges of particle diameter and 1.5 to 3 wt. % of β-wollastonite powder as a crystallization agent wherein the glass powder contains 40.0 to 45.0 wt. % of CaO, 9.0 to 20.0 wt. % of B.sub.2O.sub.3 and 40.0 to 46.0 wt. % of SiO.sub.2.

A honeycomb filter includes a honeycomb structure having a porous partition wall disposed to surround a plurality of cells; and a plugging portion provided at one end of the cell, wherein the honeycomb structure has an inflow side region including a range of up to at least 30% with respect to the total length of the honeycomb structure with the inflow end face as the starting point and an outflow side region including a range of up to at least 20% with respect to the total length of the honeycomb structure with the outflow end face as the starting point, in the extending direction of the cell of the honeycomb structure, an average pore diameter of the partition wall in the inflow side region is 9 to 14 μm and an average pore diameter of the partition wall in the outflow side region is 15 to 20 μm.

A honeycomb body having a cutout, an assembly including the honeycomb body, and a method of manufacturing. The method includes forming the honeycomb body having a matrix of intersecting walls that define a plurality of cells and channels extending longitudinally through the honeycomb body. A subset of the channels are plugged to create a plurality of plugged cells in a reinforcement region of the honeycomb body. Material is removed from the honeycomb body within the reinforcement region in accordance with a peripheral shape that passes through the plugged cells to form a cutout that extends an axial depth into the honeycomb body.

A honeycomb body having a cutout, an assembly including the honeycomb body, and a method of manufacturing. The method includes forming the honeycomb body having a matrix of intersecting walls that define a plurality of cells and channels extending longitudinally through the honeycomb body. A subset of the channels are plugged to create a plurality of plugged cells in a reinforcement region of the honeycomb body. Material is removed from the honeycomb body within the reinforcement region in accordance with a peripheral shape that passes through the plugged cells to form a cutout that extends an axial depth into the honeycomb body.

A method for fabricating multi-layer ceramic broadband radome includes thermal-spraying layers of coating materials on the radome. The assembled structure exhibits tuned RF transparency response depending on the thickness and the dielectric constant of the deposited layers. Sub-micron thick ceramic layers, which are essential for broadband performance and hard to produce due to their fragile nature, can be deposited on big and complex objects by a fast and automated process.

A method for fabricating multi-layer ceramic broadband radome includes thermal-spraying layers of coating materials on the radome. The assembled structure exhibits tuned RF transparency response depending on the thickness and the dielectric constant of the deposited layers. Sub-micron thick ceramic layers, which are essential for broadband performance and hard to produce due to their fragile nature, can be deposited on big and complex objects by a fast and automated process.

When the porous ceramic structure contains Co together with Fe or Mn, the Co content is higher than or equal to 0.1 mass % and lower than or equal to 3.0 mass % in terms of Co.sub.3O.sub.4, and when the porous ceramic structure contains Co without containing Fe and Mn, the Co content is higher than or equal to 0.2 mass % and lower than or equal to 6.0 mass % in terms of Co.sub.3O.sub.4. The ratio of the sum of the Fe content in terms of Fe.sub.2O.sub.3, the Mn content in terms of Mn.sub.2O.sub.3, and the Co content in terms of Co.sub.3O.sub.4 to the Ce content in terms of CeO.sub.2 is higher than or equal to 0.8 and lower than or equal to 9.5.