Abstract: A boron carbide sintered body having a plurality of pores, comprises a boron carbide as a main component and a plurality of graphite particles dispersed in the sinter. The graphite particles is exposed to the pores or is in the vicinity of the pores.

Abstract: A sintered ceramic composition includes at least 50 wt. % boron carbide and at least 0.01 wt. % of at least one element selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy Ho, Er, Tm, Yb, and Lu, the sintered ceramic composition being characterized by a density of at least 90% of theoretical density.

Abstract: A boron carbide based sintered body having a four-point flexural strength of at least 400 MPa and a fracture toughness of at least 2.8 MPa·m1/2, which has the following two preferred embodiments. (1) A boron carbide-titanium diboride sintered body obtained by sintering a mixed powder of a B4C powder, a TiO2 powder and a C powder while reacting them under a pressurized condition and comprising from 95 to 70 mol % of boron carbide and from 5 to 30 mol % of titanium diboride, wherein the boron carbide has a maximum particle diameter of at most 5 ?m. (2) A boron carbide-chromium diboride sintered body containing from 10 to 25 mol % of CrB2 in B4C, wherein the sintered body has a relative density of at least 90%, boron carbide particles in the sintered body have a maximum particle diameter of at most 100 ?m, and the abundance ratio (area ratio) of boron carbide particles of from 10 to 100 ?m to boron carbide particles having a particle diameter of at most 5 ?m, is from 0.02 to 0.6.

Abstract: A highly corrosion-resistant SiC material is formed on a base body by a CVD process. The SiC material contains ?-SiC crystals so oriented that the ratio of the sum of peak intensities of x-ray diffraction for (220) and (311) planes of the ?-Sic csystals to the sum of peak intensities of x-ray diffraction for (111), (200), (220), (311) and (222) planes Of the ?-SiC crystals is 0.15 or above. The SiC material may contain both ?-SiC crystals and ?-SiC crystals of 6H structure. A base body with a SiC material by a CVD process is used as an internal component member of a semiconductor device fabricating system.

Abstract: The present invention relates to a ceramic material based on based on ?-sialon (Si6?zAlzOzN), ?-sialon, a refractory hard phase comprising TiN, Ti(C,N) or TiC, an intergranular amorphous or partly crystalline phase, and containing yttrium. The ?-sialon phase has a z-value of from about 0.3 to about 0.8. The content of refractory hard phase is from about 10 to about 20 percent by weight. The material is particularly useful as cutting tool inserts for the machining of heat resistant super alloys (HRSA).

Abstract: The present invention relates to a material for use at temperatures exceeding 1200° C. and in oxidizing atmospheres consisting generally of an alloy between a metal, aluminium (Al) and carbon (C) or nitrogen (N). The invention is characterized in that the alloy has a composition MZAlYXW where M essentially consists of titanium (Ti), chromium (Cr) and/or niobium (Nb) and where X is carbon (C) or where X is nitrogen (N) and/or carbon (C) when M is titanium (Ti); and in that z lies in the range of 1.8 to 2.2, y lies in the range of 0.8-1.2 and w lies in the range 0.8-1.2, and wherein a protective oxide layer of Al2O3 is formed after heating to the mentioned temperature.

Abstract: A ceramic body that includes between about 15 volume percent and about 35 volume percent of a boron carbide irregular-shaped phase, and at least about 50 volume percent alumina, and the ceramic body has a fracture toughness (KIC, 18.5 Kg Load E&C) greater than or equal to about 4.5 MPa·m0.5.

Abstract: A material for a magnetic head slider according to the present invention is a magnetic head slider material comprised of a sintered body containing alumina and titanium carbide, in which an area percentage of an area of alumina crystal grains and titanium carbide crystal grains having a crystal grain size of not less than 200 nm nor more than 350 nm to an area of alumina crystal grains and titanium carbide crystal grains in a cut surface of the sintered body is not less than 80%.

Abstract: Ceramic materials with a matrix which contains at least one carbide, at least one carbide-forming element and carbon, and which furthermore contain a dispersed phase of carbon particles with spherical shape and an average diameter of 0.2 ?m to 800 ?m, a process for their production and their use for thermal insulation, as a protective layer in ceramic armoring against mechanical action, or as a friction layer in brake disks or clutch disks.

Abstract: A process for making a ceramic body that includes the following steps: providing a starting powder mixture, the starting powder mixture comprises between about 15 volume percent and about 35 volume percent boron carbide powder and at least about 50 volume percent alumina powder and no more than about 5 volume percent of a sintering aid; and consolidating the powder mixture at a temperature equal to between about 1400 degrees Centigrade and 1850 degrees Centigrade to achieve a ceramic with a density equal to greater than 99 percent of theoretical density.

Abstract: The magnetic head slider material of the present invention is constituted by a sintered body containing 100 parts by weight of alumina, 20 to 150 parts by weight of titanium carbide and silicon carbide in total, and 0.2 to 9 parts by weight of carbon.

Abstract: Multiphase ceramic nanocomposites having at least three phases are disclosed. Each of the at least three phases has an average grain size less than about 100 nm. In one embodiment, the ceramic nanocomposite is substantially free of glassy grain boundary phases. In another embodiment, the multiphase ceramic nanocomposite is thermally stable up to a temperature of at least about 1500° C. Methods of making such multiphase ceramic nanocomposites are also disclosed.

Abstract: A method of machining a workpiece including the steps of providing a workpiece; providing a ceramic cutting insert having a rake surface and a flank surface wherein the rake surface and the flank surface intersect to form a cutting edge and the ceramic cutting insert having a substrate that comprises between about 15 volume percent and about 35 volume percent of a boron carbide phase and at least about 50 volume percent alumina and has a fracture toughness (KIC, 18.5 Kg Load E&C) greater than or equal to about 4.5 MPa·m0.5; causing relative rotational movement between the workpiece and the ceramic cutting insert wherein the surface speed of the relative rotational movement is equal to or greater than about 457 surface meters per minute; and bringing the ceramic cutting insert and the workpiece into contact with each other so as to remove material from the workpiece.

Abstract: There are provided in accordance with embodiments of the invention metal-containing inorganic block copolymers, structures formed by self-assembly of such copolymers, and metal-containing ceramics which may be formed from such copolymers and/or structure. Methods for making such copolymers, structures and ceramics are also provided. Other embodiments are also disclosed.

Abstract: The invention relates to an improved method of manufacturing a compound having a sub-micron primary particle size such as a metal compound such as metal oxides, metaloxy hydroxides metal hydroxides, metal carbides, metal nitrides, metal carbonitrides, metal borides, electroceramics and other such compound, said method comprising the steps of: introducing a solid reactor filling material in a reactor, introducing a metal-containing precursor, a semi-metal-containing precursor, a metal-containing oxide or a semi-metal-containing oxide in said reactor, introducing a reactant or a substitution source into the said reactor, and introducing a supercritical solvent into the said reactor. These steps result in the formation of said compound in the proximity of the said solid reactor filling material.

Abstract: This disclosure describes sintered bodies comprising about 90 wt % to about 99 wt % of boron carbide, having a B:C atomic ratio ranging from 3.8 to 4.5:1; 0 to 1 wt % free carbon; 0 to 1 wt % BN or AlN, remainder an oxide binder phase; said sintered body having a uniform microstructure composed of substantially equiaxed grains of said boron carbide; the oxide binder phase comprising at least a rare earth aluminate and optionally Al2O3 or other ternary or binary phases of rare earth oxide-alumina systems; the binder phase being present in form of pockets at the multiple grain junctions and the density of no more than 2.6 g/cm3. Also described is a manufacturing process for the above described substantially pore-free, sintered boron carbide materials with high strength and fracture toughness, which can be used for production of large-area parts. This is achieved by liquid phase low temperature-low pressure hot pressing of boron carbide in an argon atmosphere.

Abstract: A sintered ceramic material comprises a crystalline phase and an intergranular phase comprising a glass phase. The material is manufactured from a starting powder being mixed with an additive comprising one or more metal from a group of Li, Na, Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Th, Pa or U. The additive is in non oxide form, or in a form which transforms to a metal or nitride during a synthesis in nitrogen atmosphere and the resulting glass phase having a high nitrogen content with a N:O ratio higher than 35:65 and a glass transition temperature above 950° C.

Abstract: A ceramic material for an optical member which shows black, wherein the ceramic material comprises a reaction-sintered sintered ceramic body prepared by synthesizing a formed body of a mixture comprising a ceramic raw material and a component that accelerates blackening, making use of a reaction sintering; and wherein the ceramic material is a porous body.

Abstract: A slip-cast article former containing ternary ceramics, particularly of carbide and nitride materials, having the formula Mn+1AXn(MAX), where M is a transition metal, A is an element from Groups IA and IVA of the periodic table, X is nitrogen or carbon and n is 1, 2, or 3. The ternary ceramic article may be a glove or condom former. A process for making a ternary ceramic article employing a slip cast method.

Abstract: A ceramic body, as well as a method of making the ceramic body, wherein in one aspect a hot-pressing method is used to produce the ceramic body. In another aspect, a sintering to full density method is used to produce the ceramic body. The hot-pressed ceramic body contains between about 15 volume percent and about 35 volume percent of a boron carbide phase and at least about 50 volume percent of alumina, and the substrate has a fracture toughness (KIC, 18.5 Kg Load E&C) greater than or equal to about 4.5 MPa·m0.5. The sintered to full density ceramic body contains between about 15 volume percent and about 50 volume percent of a boron carbide irregular-shaped phase and at least about 50 volume percent alumina.

Abstract: The present invention provides sliding members respectively having sliding surfaces opposed to each other for creating dynamic pressure in a fluid, in which the sliding surfaces are formed of ceramics containing crystal grains of Al2O3, crystal grains of TiC contained in the crystal grains of Al2O3, and crystal grains of TiC existing independently of the crystal grains of Al2O3, and having a TiC content of 5 to 20 mass % in the total amount of Al2O3 and TiC, and the respective volume resistivity values R1 and R2 of the ceramics forming the sliding surfaces are within a range simultaneously satisfying equations (1) to (3) to prevent spark discharges from being induced between the sliding surfaces, and a fluid dynamic pressure bearing and a motor to which the configuration is applied: 106 ?·cm<R1?1012 ?·cm??(1) 106 ?·cm<R2?1012 ?·cm??(2) |R1?R2|?105 ?·cm??(3)

Abstract: A slip-casted article former containing ternary ceramics, particularly of carbide and nitride materials, having the formula M.sub.n+1AX.sub.n (MAX), where M is a transition metal, A is an element from Groups IIIA and IVA of the periodic table, X is nitrogen or carbon and n is 1, 2, or 3. The ternary ceramic article may be a glove or condom former. A process for making a ternary ceramic article employing a slip cast method.

Abstract: Composite materials containing silicon, titanium, carbon, and nitrogen, formed by spark plasma sintering of ceramic starting materials to a high relative density, demonstrate unusually high electrical conductivity as well as high-performance mechanical and chemical properties including hardness, fracture toughness, and corrosion resistance. This combination of electrical, mechanical, and chemical properties makes these composites useful as electrical conductors in applications where high-performance materials are needed due to exposure to extreme conditions such as high temperatures, mechanical stresses, and corrosive environments.

Abstract: A low-thermal-expansion, rigid and wear-resistant ceramic is provided. The low-thermal-expansion ceramic of the invention includes 60 vol % to 99.9 vol % of at least one selected from the group consisting of cordierite, spodumene and eucryptite and 0.1 vol % to 40 vol % of at least one selected from the group consisting of carbides, nitrides, borides and silicides of group IVa elements, group Va elements and group VIa elements, and boron carbide. The ceramic has a porosity of 0.5% or less and a thermal expansion coefficient, at 10° C. to 40° C., of 1.5×10?6/° C. or less.

Abstract: Production processes of an inorganic fiber-bonded ceramic component comprising inorganic fibers mainly comprising Si, M, C and O, an inorganic substance mainly comprising Si and O and boundary layers comprising carbon as a main component; and an inorganic fiber-bonded ceramic component comprising inorganic fibers which are composed mainly of a sintered structure of SiC and contain specific metal atoms and boundary layers composed mainly of carbon, wherein a preliminary shaped material is set in a carbon die, covered with a carbon powder and then hot-pressed to load a pseudo-isotropic pressure on the preliminary shaped material; and a highly heat-resistant inorganic fiber-bonded ceramic component almost free from the occurrence of peelings of surface fibers or delamination, wherein fibers are aligned in a surface shape.

Abstract: Preparation, handling, and spray drying, in an economic and environmentally-friendly way, of slurries for the production of tungsten carbide based hard metal tools or components by the powder injection molding or extrusion route is disclosed. The slurry used is based on ethanol-water and contains metal carbide and metallic raw materials as well as stearic acid and a low concentration of polyethylenimine (PEI). The concentration of PEI is 0.01–1 wt % of the raw material weight. This combination results in low-viscous slurries, which require less use of ethanol, energy, manpower, and equipment time in their preparation, handling, and spray drying. The invention also relates to the powder obtained by using the method.

Abstract: Disclosed herein is a method to produce ceramic materials utilizing the sol-gel process. The methods enable the preparation of intimate homogeneous dispersions of materials while offering the ability to control the size of one component within another. The method also enables the preparation of materials that will densify at reduced temperature.

Abstract: The present high-strength, highly thermally conductive sintered compact of cubic boron nitride contains cubic boron nitride (cBN) grains and a binder binding the grains. More specifically, it is formed of at least 40% by volume and at most 85% by volume of cBN grains, and a binder corresponding to the remainder and formed of at least one selected from the group consisting of a nitride, a carbide, a boride, and an oxide of an element belonging to the 4a, 5a and 6a groups of the periodic table and a solid solution thereof, an aluminum compound, and an unavoidable impurity, and the cBN grains contain at most 0.03% by mass of Mg and at least 0.001% by mass and at most 0.05% by mass of Li.

Abstract: A method of making nanoscale ordered composites of covalent ceramics through block copolymer-assisted assembly. At least one polymeric precursor is mixed with a block copolymer, and self-assembly of the mixture proceeds through an annealing process. During the annealing step, the polymeric precursor cross-links to form a structure robust enough to survive both the order-disorder transition temperature the block copolymer and the pyrolysis process, yielding ordered nanocomposites of high temperature ceramic materials. The method yields a variety of structures and morphologies. A ceramic material having at least one ceramic phase that has an ordered structure on a nanoscale and thermally stable up to a temperature of at least about 800° C. is also disclosed. The ceramic material is suitable for use in hot gas path assemblies, such as turbine assemblies, boilers, combustors, and the like.

Abstract: An initial solids mixture for a later organic coating, such as pigmented coatings, films, priming coats, etc., e.g., for a coil coating method in which an initial solids mixture is applied to a substrate, e.g., broad strip, and this is thereby pre-coated, wherein the initial solids mixture includes, as additive particles, boron carbide and/or silicon carbide and/or compounds of transition elements or lanthanides, the electrical conductivity of which is selected to be in the metallic range (?>102 1/?cm and ?<107 1/?cm), during the later coating, the additive particles have a continuous physical connection in at least one spatial direction.

Abstract: A tough wear-resistant hard member that includes a hard composite member and a support that has a surface area adjacent to the hard composite member wherein the hard composite member is affixed to the support over at least a portion of the adjacent surface area of the support. The hard composite member includes a plurality of discrete hard constituents distributed in the hard composite member wherein each one of the discrete hard constituents is of a size so as to have a surface area between about 0.001 square inches and about 16 square inches. The hard composite member further contains a matrix powder that includes particles wherein substantially all of the hard particles have a size smaller than the size of the hard constituents.

Abstract: A compound having a space spinel structure and the formula Si3-x Cx N4 wherein 0<x?1. An example of the compound is spinel silicon carbonitride. The compound of the invention may be made by providing a silicon carbo-diimide compound and subjecting the compound to elevated temperature and pressure conditions.

Abstract: An electroconductive low thermal expansion ceramic sintered body is disclosed which containing a ?-eucryptite phase in a quantity of not less than 75 vol. % and not more than 99 vol. % and having an absolute value of thermal expansion coefficient of not more than 1.0×10?7/K at a temperature of 0° C. to 50° C., a volumetric specific resistance of not more than 1.0×107 ?·cm, and a specific rigidity of not less than 40 GPa/g/cm3.

Abstract: Compositions including modified carbide-containing nanorods and/or modified oxycarbide-containing nanorods and/or modified carbon nanotubes bearing carbides and oxycarbides and methods of making the same are provided. Rigid porous structures including modified oxycarbide-containing nanorods and/or modified carbide containing nanorods and/or modified carbon nanotubes bearing modified carbides and oxycarbides and methods of making the same are also provided. The compositions and rigid porous structures of the invention can be used either as catalyst and/or catalyst supports in fluid phase catalytic chemical reactions. Processes for making supported catalyst for selected fluid phase catalytic reactions are also provided.

Abstract: A highly corrosion-resistant SiC material is formed on a base body by a CVD process. The SiC material contains ?-SiC crystals so oriented that the ratio of the sum of peak intensities of x-ray diffraction for (220) and (311) planes of the ?-SiC csystals to the sum of peak intensities of x-ray diffraction for (111), (200), (220), (311) and (222) planes of the ?-Sic crystals is 0.15 or above. The SiC material may contain both ?-SiC crystals and ?-SiC crystals of 6H structure. A base body with a SiC material by a CVD process is used as an internal component member of a semiconductor device fabricating system.

Abstract: A ceramic composite made by compacting a starting powder blend. The composite includes between about 50 volume percent and about 99 volume percent of a ceramic matrix; and between about 1 volume percent and about 50 volume percent as-processed silicon carbide whiskers. The ceramic composite having a fracture toughness (KIC) of greater than about 4.0 MPam1/2. The ceramic has a silicon carbide whisker density as measured in whiskers per square millimeter equal to or less than about 1500 times the volume percent of silicon carbide whiskers, but in a density sufficient for the ceramic composite to have the fracture toughness.

Abstract: An electrical resistance heating element operable at extremely high temperature, up 2300° C. when used in a vacuum or in a reducing atmosphere, and up to bout 1200° C. when used in an oxidizing atmosphere. The element is formed substantially from titanium silicon carbide (Ti3SiC2), which is readily workable to enable it to be produced in different forms. It also has a higher mechanical strength than that of graphite heating elements.

Abstract: A protective coating for a carbon-containing component comprises a material selected from the group consisting of non-stoichiometric silicon and carbon; non-stoichiometric silicon and oxygen; non-stoichiometric silicon and nitrogen; compounds of silicon, oxygen, and carbon; compounds of silicon, oxygen and nitrogen; compounds of silicon, nitrogen, and carbon; and silicon.

Abstract: A method of making tungsten carbide and a method of making a densified tungsten carbide-containing ceramic body with a transverse rupture strength greater than 300,000 psi are disclosed.

Abstract: Compositions including oxycarbide-based nanorods and/or carbide-based nanorods and/or carbon nanotubes bearing carbides and oxycarbides and methods of making the same are provided. Rigid porous structures including oxycarbide-based nanorods and/or carbide based nanorods and/or carbon nanotubes bearing carbides and oxycarbides and methods of making the same are also provided. The compositions and rigid porous structures of the invention can be used either as catalyst and/or catalyst supports in fluid phase catalytic chemical reactions. Processes for making supported catalyst for selected fluid phase catalytic reactions are also provided. The fluid phase catalytic reactions catalyzed include hydrogenation, hydrodesulfurisation, hydrodenitrogenation, hydrodemetallisation, hydrodeoxigenation, hydrodearomatization, dehydrogenation, hydrogenolysis, isomerization, alkylation, dealkylation and transalkylation.

Abstract: The present invention provides a sintered silicon carbide jig production method capable of simply increasing the purity of a sintered silicon carbide jig. A method of producing a sintered silicon carbide jig comprising a process in which a second sintered body is heated at a temperature rising rate of 3 to 5° C./min up to heating treatment temperature selected in the range of 2200 to 2300° C. under an argon atmosphere, kept at the same heating treatment temperature for 3 hours, and cooled at a temperature lowering rate of 2 to 3° C./min down to 1000° C.

Abstract: An improved ceramic/metal composite material is disclosed which is fully reacted with aluminum. The composite is made from a ceramic preform, such as silicon carbide, having a binding agent, such as silica, that is contacted with a metal mixture or alloy, such as aluminum/silicon, that reacts with the binding agent to form a ceramic/metal composite material. Also disclosed is a method of making the improved composite material and articles made incorporating the material.

Abstract: A sintered cubic boron nitride (cBN) compact for use in a tool is composed of between about 60 and 80 vol-% cBN having a volumetric mean particle size of between about 3 to 6 &mgr;m and between about 40 and 20 vol-% of a ceramic binder phase. The ceramic binder is composed of between about 20 and 60 vol-% of one or more of a carbide, nitride, or boride of a Group IVB or VIB metal, and between about 40 and 80 vol-% of one or more of carbides, nitrides, borides, or oxides of aluminum. The cBN compact additionally contains between about 3 and 15 wt-% tungsten. The cBN compacts are especially useful in machining iron and like chemically reactive parts, especially where such parts are powder metal parts.

Abstract: After an alloy powder including W, Cr, at least one of Ti, Zr, and Hf, and at least one of V, Nb, and Ta is produced, the alloy powder, a powdery carbon material, and a catalyst are heat-treated in the presence of a nitrogen gas. The alloy powder is carbonitrided into a multicomponent ceramics powder, and sintered into a sintered body. Alternatively, a powder of a first substance including at least two of Ti, Al, V, Nb, Zr, Hf, Mo, Ta, Cr, and W is molded into a molded body. Then, the surface of the molded body is surrounded by a second substance including a metal element which is not contained in the powder of the first substance, and the molded body is heat-treated in an atmosphere in which N is present. A porous sintered body thus produced is crushed into a multicomponent ceramics powder.

Abstract: A ceramic material suitable for use in production of paving tiles, construction tiles, flooring in offices, flooring in machinery plants and so forth is obtained by a method comprising steps of mixing defatted bran derived from rice bran with a thermosetting resin before kneading, subjecting a kneaded mixture thus obtained to a primary firing in an inert gas at a temperature in a range of 700 to 1000° C., pulverizing the kneaded mixture after the primary firing into carbonized powders, kneading the carbonized powders with which ceramic powders, a solvent, and a binder as desired are mixed into a plastic workpiece (kneaded mass), pressure-forming the plastic workpiece at pressure in a range of 10 to 100 MPa, and subjecting a formed plastic workpiece thus obtained again to firing in an inert gas atmosphere at a temperature in a range of 100 to 1400° C.

Abstract: A hybrid insulation material comprises of porous ceramic substrate material impregnated with nanoporous material and method of making the same is the topic of this invention. The porous substrate material has bulk density ranging from 6 to 20 lb/ft3 and is composed of about 60 to 80 wt % silica (SiO2) 20 to 40 wt % alumina (Al2O3) fibers, and with about 0.1 to 1.0 wt % boron-containing constituent as the sintering agent. The nanoporous material has density ranging from 1.0 to 10 lb/ft3 and is either fully or partially impregnated into the substrate to block the pores, resulting in substantial reduction in conduction via radiation and convention. The nanoporous material used to impregnate the fiber substrate is preferably formed from a precursor of alkoxysilane, alcohol, water, and an acid or base catalyst for silica aerogels, and from a precursor of aluminum alkoxide, alcohol, water, and an acid or base catalyst for alumina aerogels.

Abstract: A transition metal-containing ceramic made by the process comprising the step of pyrolyzing an organometallic linear polymer containing at least one metallocenylene unit, at least one silyl or siloxyl unit, and at least one acetylene unit to form a ceramic; where the ceramic has a ceramic yield of at least about 75% by weight. A transition metal-containing ceramic made by the process comprising the steps of: forming an organometallic linear polymer containing at least one metallocenylene, at least one silyl or siloxyl unit, and at least one acetylene unit; crosslinking said linear polymer through the acetylene units, thereby forming a thermoset; and pyrolyzing said thermoset to form a ceramic; where the ceramic has a ceramic yield of at least about 75% by weight.

Abstract: A honeycomb structure made of a silicon carbide-based porous body and having a number of through-holes extending in the axial direction, separated by partition walls. The strength and Young's modulus of the silicon carbide-based porous body satisfy the following relation: Strength (MPa)/Young's modulus (GPa)≧1.1. The honeycomb structure contains refractory particles such as silicon carbide particles and the like and yet can be produced at a relatively low firing temperature at a low cost, has a high strength and a high thermal shock resistance, and can be suitably used, for example, as a filter for purification of automobile exhaust gas by a treatment such as plugging of through-channel at its inlet or outlet, or as a catalyst carrier, even under a high SV condition.

Abstract: An alumina-based composite sintered material comprising alumina as a main ingredient and containing one or more carbonitridation products of groups IVa, Va and VIa of the periodic table and/or two or more carbonitridation products of solid solutions of groups IVa, Va and VIa of the periodic table. The content of nitrogen solid solute in the carbonitridation product increases from the interior to the surface of the sintered material, and the Vickers hardness at the surface of the sintered material is 19.5 GPa or more.

Abstract: Composite cordierite honeycomb structures especially suitable for diesel exhaust filtration applications comprise a non-oxide polycrystalline phase constituting 10-70% by weight, with the remainder of the ceramic material constituting a cordierite phase, the non-oxide polycrystalline phase being selected from the group consisting of carbides, nitrides, and borides. Preferably the non-oxide phase is either polycrystalline silicon carbide or polycrystalline silicon nitride and has a particle aspect ratio of less than 3. Inventive ceramic bodies are porous with an open porosity of at least 30%, preferably between 40% and 60%, and a median pore size of at least 5 micrometers, more preferably greater than 8 micrometers and less than 12 micrometers.