There is provided a platy zinc oxide sintered compact containing 0.80 wt % or less at least one first dopant element selected from the group consisting of Al, Ga and In, the balance consisting essentially of ZnO and optionally at least one second dopant element selected from the group consisting of Br, Cl, F, Sn, Y, Pr, Ge, B, Sc, Si, Ti, Zr, Hf, Mn, Ta, W, Cu, Ni, Cr, La, Gd, Bi, Ce, Sr and Ba, the second dopant element being optional component, wherein the (002)-plane orientation in the plate surface is 60% or more. The zinc oxide sintered compact of the present invention has excellent properties such as high orientation in addition to transparency and conductivity.

A method for producing a transparent alumina sintered body according to the present invention includes (a) a step of preparing an alumina raw material powder containing a plate-like alumina powder having an aspect ratio of 3 or more and a fine alumina powder having an average particle diameter smaller than that of the plate-like alumina powder so that, when a mixing ratio of the plate-like alumina powder to the fine alumina powder in terms of mass ratio is assumed to be T:(100T), T is 0.001 or more and less than 1, and so that a mass ratio R1 of F relative to Al in the alumina raw material powder is less than 15 ppm; (b) a step of forming a raw material for forming containing the alumina raw material powder into a compact; and (c) a step of sintering the compact so as to obtain a transparent alumina sintered body.

The present invention provides a method of producing a honeycomb structured body having excellent mechanical strength. The present invention relates to a method of producing a honeycomb structured body including a honeycomb fired body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween, the method including: a raw material mixing step of preparing a raw material paste containing ceria-zirconia composite oxide particles, alumina particles, an inorganic binder, and alumina fibers; a molding step of molding the raw material paste into a honeycomb molded body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween; a drying step of drying the honeycomb molded body obtained in the molding step; and a firing step of firing the honeycomb molded body dried in the drying step into a honeycomb fired body, wherein the percentage of amorphous alumina fibers in the alumina fibers for use in the raw material mixing step is 50 to 100 wt %.

The present invention provides a method of producing a honeycomb structured body having excellent mechanical strength. The present invention relates to a method of producing a honeycomb structured body including a honeycomb fired body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween, the method including: a raw material mixing step of preparing a raw material paste containing ceria-zirconia composite oxide particles, alumina particles, an inorganic binder, and inorganic fibers; a molding step of molding the raw material paste into a honeycomb molded body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween; a drying step of drying the honeycomb molded body obtained in the molding step; and a firing step of firing the honeycomb molded body dried in the drying step into a honeycomb fired body, wherein the raw material mixing step includes pre-mixing of the inorganic binder and the inorganic fibers.

The use of magnesium oxide, reactive alumina and aluminium oxide as a base provides for a new erosion-resistant material upon sintering.

Disclosed is a honeycomb filter for collecting fine particles that includes a wall portion formed from a base material containing ceria-zirconia composite oxide and an inorganic binder. The wall portion has a gas permeability coefficient of 1.0 m.sup.2 or greater and 3.0 m.sup.2 or less.

Disclosed is a honeycomb filter for collecting fine particles that includes a wall portion formed from a base material containing ceria-zirconia composite oxide and an inorganic binder. In a pore diameter distribution in which a pore diameter and a log differential pore volume measured through mercury porosimetry are respectively represented by a horizontal axis and a vertical axis, the wall portion has a peak in a range in which the pore diameter is greater than or equal to 0.01 m and less than 1 m and a peak in a range in which the pore diameter is greater than or equal to 1 m and less than or equal to 50 m.

The present invention relates to a honeycomb structure having promoter particles and a binder phase interposed between the promoter particles, and a method for manufacturing the same. The promoter particles contain at least first promoter particles made of a ceria-zirconia solid solution. The binder phase, in each of which a number of inorganic binder particles are aggregated with each other, with -alumina being a main component, contain one or two of Fe and Cr dissolved in -alumina. The honeycomb structure has a specific surface area at a ratio of 90% or more of after heating to before heating at a temperature of 1200 C.

A bonded abrasive article includes elongate shaped abrasive particles. The elongate shaped abrasive particles comprise an elongate shaped ceramic body having opposed first and second ends joined to each other by at least two longitudinal sidewalls. At least one of the at least two longitudinal sidewalls is concave along its length. At least one of the first and second ends is a fractured surface.

The use of magnesium oxide, reactive alumina and aluminium oxide as a base provides for a new erosion-resistant material upon sintering.