Polycrystalline cubic boron nitride compact include a body having sintered microcrystalline cubic boron nitride in a matrix of binder material. The microcrystalline cubic boron nitride particles have a size ranging from 2 microns to 50 microns. The particles of microcrystalline cubic boron nitride include a plurality of sub-grains, each sub-grain having a size ranging from 0.1 micron to 2 microns. The compacts are manufactured in a high pressure—high temperature (HPHT) sintering process. The compacts exhibit intergranular defect formation following introduction of wear. The sub-grains promote crack propagation based on micro-chipping rather than on a cleavage mechanism and, in sintered bodies, cracks propagate intergranularly rather than intragranularly, resulting in increased toughness and improved wear characteristics as compared to monocrystalline cubic boron nitride. The compacts are suitable for use as abrasive tools.

A ZrO.sub.2—Al.sub.2O.sub.3-based ceramic sintered compact containing tetragonal ZrO.sub.2 particles having a crystallite size of from 5 to 20 nm as a main component and having an α-Al.sub.2O.sub.3 crystallite size of not greater than 75 nm and a relative density of not less than 99% can be produced by preparing a Y.sub.2O.sub.3 partially stabilized ZrO.sub.2—Al.sub.2O.sub.3-based powder having a molar ratio (mol %) of zirconia (ZrO.sub.2) and yttria (Y.sub.2O.sub.3) of from 96.5:3.5 to 97.5:2.5 and a mass ratio (mass %) of ZrO.sub.2 containing Y.sub.2O.sub.3 and alumina (Al.sub.2O.sub.3) of from 85:15 to 75:25, molding this powder by cold isostatic pressing, and then performing sintering to a high density by microwave sintering for 45 to 90 min in an inert gas atmosphere at 1200 to 1400° C. When performing microwave sintering, a heating rate is preferably from 5 to 20° C./min up to 600° C. and from 50 to 150° C./min at 600° C. or higher.

Methods of determining and controlling the deformability of ceramic materials, as a nonlimiting example, YSZ, particularly through the application of a flash sintering process, and to ceramic materials produced by such methods. Such a method includes providing a nanocrystalline powder of a ceramic material, making a compact of the powder, and subjecting the compact to flash sintering by applying an electric field and thermal energy to the compact.

The present disclosure provides a monolith substrate used for an exhaust gas purifying catalyst that improves purification performance, a method for producing such monolith substrate, and an exhaust gas purifying catalyst comprising such monolith substrate. The present disclosure relates to a monolith substrate comprising an alumina-ceria-zirconia composite oxide and alumina, a method for producing such monolith substrate, and an exhaust gas purifying catalyst comprising such monolith substrate.

A sintered body including zirconia containing a stabilizer, wherein the sintered body has a monoclinic fraction of 0.5% or more and has a three-point bending strength of more than 1450 MPa as measured by a three-point bending test according to JIS R 1601. - - -

The present invention provides means capable of satisfactorily exhibit the properties inherent in the inorganic particle and the constituent material of the coating layer, such as obtaining high dispersibility and high mechanical properties in the coated particle that contains the inorganic particle having at least the inorganic substance capable of forming an inorganic oxide on a surface, and the coating layer with which the inorganic particle is coated. The present invention relates to a coated particle that contains an inorganic particle having at least an inorganic substance capable of forming an inorganic oxide on a surface, and a coating layer with which the inorganic particle is coated, in which the amount of the inorganic oxide per unit surface area of the inorganic particle does not exceed 0.150 mg/m.sup.2.

An aluminium oxide ceramic material containing the following components:

TABLE-US-00001 component wt.-% Al.sub.2O.sub.3  95.0 to 99.989 MgO 0.001 to 0.1 Eu, calculated as Eu.sub.2O.sub.3  0.01 to 1.0.

Disclosed herein are methods of forming a hydrous kaolin clay product. The method can include (i) refining coarse crude kaolin clay to form a refined, coarse kaolin clay, and/or refining a tertiary, fine crude kaolin clay to form a refined, fine, hydrous kaolin clay, (ii) centrifuging the refined, coarse kaolin clay; the refined, fine, hydrous kaolin clay, or a blend thereof to provide a hydrous kaolin stream, and (iii) refining the hydrous kaolin stream to form the hydrous kaolin clay product. The hydrous kaolin stream can be blended with a delaminated, coarse kaolin clay, prior to refining the hydrous kaolin stream. The hydrous kaolin clay product can have a total alkali content of 0.2% or less by weight of the hydrous kaolin clay product. Compositions including cordierite ceramics, industrial coatings, paints, adhesives, inks, and fillers comprising the hydrous kaolin clay product are also described herein.

A process for fabricating pre-sintered zirconia blanks that are then computer machined and sintered to form dental appliances having highly advantageous features. The principal steps of a preferred embodiment of that process comprise; a) preparing a ceramic slurry of zirconia powder; b) subjecting the slurry to attrition milling down to about a 5-29 nm crystallite size; c) preparing a vacuum assisted and pressure assisted slip casting mold and pouring the milled slurry into the slip-casting mold; d) after casting, excess slurry is poured from the mold and a consolidated zirconia blank is removed; e) drying the blank and pre-sintering it to form solid blanks ready for CAD/CAM machining and sintering to net shape. The attrition is run with ball bearings that are of the sample material to prevent contamination. It also is run, up to 24 hours, to break down the crystallites to overcome the high density of zirconia.

To provide a zirconia sintered body having both excellent translucency and bending strength, specifically a zirconia sintered body having both translucency and strength suitable as a denture for front tooth, and a process for its production. A translucent zirconia sintered body containing more than 4.0 mol % and at most 6.5 mol % of yttria and less than 0.1 wt % of alumina, and having a relative density of at least 99.82%, a total light transmittance of at least 37% and less than 40% to light with a wavelength of 600 nm at a thickness of 1.0 mm, and a bending strength of at least 500 MPa, and a process for its production.