Abstract: The present invention relates to a complete solid solution powder used for preparing a cermet composite sintered body, and method for preparing thereof under high temperature. Particularly, the present invention is directed to a complete solid solution powder which can improve, to a great extent, toughness of a cermet sintered body which is used for high-speed cutting tool materials and die materials in the field of metal working, such as various machine industries and automobile industry, and method for preparing thereof under high temperature.

Abstract: A method for producing ceramic materials utilizing the sol-gel process enables 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 densify at reduced temperatures. Applications of the compositions include filters, solid-oxide fuel cells, membranes, ceramic cutting tools and wear and auto parts. In one example, 10 g of AlCl6.6H2O is added to a 150 ml beaker and dissolved in 10 g EtOH and 1 g H2O. While stirring, 0.456 g of B4C powder is added. Then 9.6 g of propylene oxide is added. The gel sets up in about 10 minutes and is dried overnight. It is then washed with 1% NH4OH and air dried to yield 3.969 g of Al2O3/B4C xerogel.

Abstract: A method for diffusing titanium and nitride into a base material having a generally compact, granular microstructure (e.g., carbide). The method generally includes the steps of providing a base material having a generally compact, granular microstructure; providing a salt bath which includes sodium dioxide and a salt selected from the group consisting of sodium cyanate and potassium cyanate; dispersing metallic titanium formed by electrolysis of a titanium compound in the bath; heating the salt bath to a temperature ranging from about 430° C. to about 670° C.; and soaking the base material in the salt bath for a time of from about 10 minutes to about 24 hours. In accordance with another aspect of the present invention, the base material may further be treated with conventional surface treatments or coatings.

Abstract: Boron carbide ceramics produced by spark sintering methods have more desirable mechanical properties than conventionally produced carbides. The boron carbide ceramics include amorphous boron, amorphous carbon, and Al2O3 powder as a sintering aid. The boron carbides may also contain a carbon nano fiber in a nearly homogeneously dispersed state. The sintered compact has a relative density of a boron carbide ceramic of approximately not less than 99%. The boron carbide ceramics are prepared preferably by subjecting a mixed powder of the starting raw materials and the carbon nano fiber to simultaneous synthesis and sintering using the spark plasma sintering method.

Abstract: A matrix powder for forming a matrix bit body, wherein the matrix powder includes: a plurality of carbide particles; and a plurality of first metal binder particles having an aspect ratio of at least about 3. Drill bits formed from metal binder particles having an aspect ratio of at least about 3 and methods of forming such bits.

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 growing method of a SiC single crystal includes the steps of thermal treatment of a high purity SiC source for decreasing a specific surface area and increasing a ratio of ?-phase and making a mole fraction of C greater than that of Si in the source, providing the SiC source into a crucible, arranging a SiC seed in the crucible, and growing the SiC single crystal by heating the SiC source.

Abstract: A ceramic glow plug which prevents the occurrence of damage on a small diameter portion formed on a rear end portion of a ceramic heater fixed in a metallic outer sleeve. The rear end portion of the ceramic heater is positioned inside the metallic outer sleeve, and the small diameter portion is formed on the rear end portion. The rear-end small diameter portion of the ceramic heater is connected to an electrode lead-out member for taking out a positive electrode of a heat generating material. Granulated powder (alumina, for example) made of inorganic insulating material is filled in around a connecting portion of the ceramic heater in the metallic outer tube and the electrode lead-out-wire, and in addition, an insulating material is sealed outside the granulated powder. Thereafter, swaging is performed to bring the insulating material into a highly dense state thus fixing the electrode lead-out wire and an electrode lead-out rod in the metallic outer sleeve.

Abstract: An aspect of the present invention is to provide an economical production technology for obtaining a dense boron carbide ceramic product without impairment to excellent mechanical properties, which boron carbide ceramics are inherently equipped with, by conducting heating under normal pressure without application of pressure and without needing addition of a large amount of a sintering additive to a raw material or needing any special additive or treatment. The present invention provides a production process in which, upon heating a boron carbide green body under normal pressure without application of pressure after pressing a boron carbide powder material to obtain the boron carbide green body, the boron carbide green body is heated with one of a powder, green body or sintered body, which contains at least one of aluminum and silicon, being disposed in a furnace.

Abstract: A mixed powder and a sintered body obtained by sintering the mixed powder. The mixed powder includes a solid-solution powder with complete solid-solution phase. The solid-solution powder includes a carbide or a carbonitride of at least two metals selected, including Ti, from metals of Groups IVa, Va and VIa of the periodic table, or a mixture thereof. A mixed cermet powder and a cermet obtained by sintering the mixed cermet powder are also disclosed. The mixed cermet powder includes at least a cermet powder with complete solid-solution phase. The cermet powder includes a carbide or a carbonitride of at least two metals selected, including Ti, from metals of Groups IVa, Va and VIa of the periodic table, or a mixture thereof, and at least one metal selected from the group consisting of Ni, Co and Fe. Also disclosed are a sintered body and a fabrication method of a cermet.

Abstract: A method of forming a nanoscale ceramic composite generally includes modifying a polymeric ceramic precursor, mixing the modified polymeric ceramic precursor with a block copolymer to form a mixture, forming an ordered structure from the mixture, wherein the modified polymeric ceramic precursor selectively associates with a specific type of block of the block copolymer, and heating the ordered structure for a time and at a temperature effective to form the nanoscale ceramic composite.

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: The present invention relates to a rotary cutter knife of a cemented carbide comprising a hard phase comprising WC and a binder phase wherein the cemented carbide comprises, in wt-%, from about 7 to about 12 Co+Ni, with a weight ratio Co/Ni of from about 0 to about 4, from about 0.5 to about 3 Cr and from about 0.1 to about 0.3 Mo.

Abstract: An object is to provide a sintered body having a sufficiently higher polishing rate than a conventional AlTiC sintered body and providing a sufficiently smooth air bearing surface. The sintered body according to the present invention consists of Al2O3 and a compound represented by the chemical formula (1) below: TiCxOy??(1) wherein x+y?1, x>0 and 0.3<y?0.6.

Abstract: In a method of forming a chalcogenide compound target, a first powder including germanium carbide or germanium is prepared, and a second powder including antimony carbide or antimony is prepared. A third powder including tellurium carbide or tellurium is prepared. A powder mixture is formed by mixing the first to the third powders. After a shaped is formed body by molding the powder mixture. The chalcogenide compound target is obtained by sintering the powder mixture. The chalcogenide compound target may include a chalcogenide compound that contains carbon and metal, or carbon, metal and nitrogen considering contents of carbon, metal and nitrogen, so that a phase-change material layer formed using the chalcogenide compound target may stable phase transition, enhanced crystallized temperature and increased resistance. A phase-change memory device including the phase-change material layer may have reduced set resistance and driving current while improving durability and sensing margin.

Abstract: Inorganic fibers consisting substantially of silicon, carbon, oxygen and a transition metal, having a fiber size of no greater than 2 ?m and having fiber lengths of 100 ?m or greater.

Abstract: The composite sintered body of the invention is a composite sintered body, containing 20 volume % or more and 80 volume % or less of cubic boron nitride particles, and a binder; wherein the binder contains at least one selected from the group consisting of nitrides, carbides, borides, and oxides of elements in the group 4a, elements in the group 5a, and elements in the group 6a in the periodic table, and solid solutions thereof, at least one selected from the group consisting of simple substances of Zr, Si, Hf, Ge, W and Co, compounds thereof, and solid solutions thereof, and a compound of Al; and when the composite sintered body contains therein W and/or Co, the total weight of the W and/or Co is less than 2.0 weight % and further the composite sintered body contains therein one or more of the Zr, Si, Hf and Ge (hereinafter referred to as “X”), and when the composite sintered body contains the X, the amount of each of the X is 0.005 weight % or more and less than 2.0 weight %, X/(X+W+Co) is 0.

Abstract: A heating apparatus comprising an energetic nanolaminate film that produces heat when initiated, a power source that provides an electric current, and a control that initiates the energetic nanolaminate film by directing the electric current to the energetic nanolaminate film and joule heating the energetic nanolaminate film to an initiation temperature. Also a method of heating comprising providing an energetic nanolaminate film that produces heat when initiated, and initiating the energetic nanolaminate film by directing an electric current to the energetic nanolaminate film and joule heating the energetic nanolaminate film to an initiation temperature.

Abstract: A novel process for the preparation of boron carbide, boron nitride and silicon carbide powders comprises carbidization or nitrization step of boron oxide or silicon oxide respectively, using nanoparticles substrates.

Abstract: Greater emphasis has been placed on smoothness of the floating surface for the applications with floating height of 10 nm or less. To obtain a smooth floating surface, it must be polished with diamond abrasive having a mean particle size of 0.1 ?m or less, and conventional ceramic sintered body has poor machinability and it is impossible to use the magnetic heads made of this ceramic sintered body at a floating height of 10 nm or less. The ceramic sintered body according to the present invention contains Al2O3 crystal grains, internal TiC crystal grains existing in the Al2O3 crystal grains and external TiC crystal grains other than the internal TiC crystal grains. The Al2O3 crystal grains and the external TiC crystal grains retain stress caused by the difference in thermal expansion coefficient remaining after sintering, so that the Al2O3 crystal grains and the external TiC crystal grains pull each other in the interface therebetween.

Abstract: Disclosed herein is a material for altering electromagnetic radiation incident on the material. The material disclosed herein comprises carbon nanotubes having a length (L) that meets the following formula (1): L?½ ???(1) where ? is the wavelength of the electromagnetic radiation incident on the material. Also disclosed herein are methods of altering electromagnetic radiation, including mitigating, intensifying, or absorbing and re-transmitting electromagnetic radiation using the disclosed material.

Abstract: A treated refractory material includes a porous refractory material having one or more protective materials disposed within pores of the refractory material. Methods of preparing the treated refractory material are also provided. The treated refractory material provides protection from the penetration of slag and extends the service life of the refractory material.

Abstract: This chemical vapor synthesis process was designed so that a metal carbide precursor and a secondary metal precursor are separately or together fed into each evaporator in a reactor by specially designed precursor feeders, either simultaneously or sequentially. The reduction and carburization of the vaporized precursors by gaseous mixtures produces carbide-metal nanocomposite powders. The product can be a very uniform mixture of the constituent powders or a uniform agglomerate, which is important to ensure a high quality of bulk cemented metal carbide product after consolidation and sintering. These nanocomposite powders can be readily characterized using XRD, carbon analyzer and TEM.

Abstract: Disclosed are a solid-solution powder, a method for preparing the solid-solution powder, a cermet powder including the solid-solution powder, a method for preparing the cermet powder, a cermet using the cermet powder and a method to prepare the cermet. According to the present invention, the problem of low toughness due to high hardness that conventional cermets (especially TiC or Ti(CN) based cermet) have is resolved because a complete solid-solution phase without core/rim structure is provided to the cermets as a microstructure thereof, and in which further increased the hardness as well as the toughness, thereby substantially and considerably increasing general mechanical properties of materials using the cermet, and thus substituting WC—Co Hard material and allowing manufacturing of cutting tools with high hardness and toughness.

Abstract: The present invention concerns a method of producing an ultrahard abrasive composite material having a desirable overall thermal expansion coefficient mismatch, between the ultrahard particles and their matrix materials. The method includes the steps of providing a volume fraction of ultrahard particles having a pre-determined thermal expansion coefficient; determining the volume fraction and thermal expansion coefficient of a matrix material that would be required to produce an ultrahard composite material having a desired overall thermal expansion coefficient mismatch; contacting the ultrahard particles and the matrix material to form a reaction volume; and consolidating and sintering the reaction volume at a pressure and a temperature at which the ultrahard particles are crystallographically or thermodynamically stable.

Abstract: The invention relates to a fired refractory ceramic product. According to the invention, this generic term encompasses both shaped and unshaped products. Shaped products are ones which have a defined shape so that they can be manufactured in finished form on the premises of the manufacturer. Shaped products include: bricks, nozzles, tubes, stoppers, plates, etc. The term unshaped products includes ones which are usually produced by the user from a corresponding composition. They include bases for furnaces which are cast from a composition but also repair compositions, etc.

Abstract: The invention provides a method of forming a dense, shaped article, such as a crucible, formed of a refractory material, the method comprising the steps of placing a refractory material having a melting point of at least about 2900° C. in a mold configured to form the powder into an approximation of the desired shape. The mold containing the powder is treated at a temperature and pressure sufficient to form a shape-sustaining molded powder that conforms to the shape of the mold, wherein the treating step involves sintering or isostatic pressing. The shape-sustaining molded powder can be machined into the final desired shape and then sintered at a temperature and for a time sufficient to produce a dense, shaped article having a density of greater than about 90% and very low open porosity. Preferred refractory materials include tantalum carbide and niobium carbide.

Abstract: A metal carbide ceramic fiber having improved mechanical properties and characteristics and improved processes and chemical routes for manufacturing metal carbide ceramic fiber. Metal carbide ceramic fibers may be formed via reaction bonding of a metal-based material (e.g. boron) with the inherent carbon of a carrier medium. One embodiment includes a method of making a metal carbide ceramic fiber using VSSP to produce high yield boron carbide fiber. Embodiments of the improved method allow high volume production of high density boron carbide fiber. The chemical routes may include a direct production of boron carbide fiber from boron carbide powder (B4C) and precursor (e.g. rayon fiber) having a carbon component to form a B4C/rayon fiber that may be processed at high temperature to form boron carbide fiber, and that may be subsequently undergo a hot isostatic pressing to improve fiber purity. Another route may include a carbothermal method comprising combining boron powder (B) with a precursor (e.g.

Abstract: A method for reducing thermal conductivity in thermal barrier coatings broadly includes the steps of depositing a mixture containing a ceramic matrix and a metallic dispersant capable of forming a metal oxide upon a substrate to form one or more layers; and heating the layers at a temperature and for a time sufficient to oxidize the metallic dispersant and form one or more layers of a thermal barrier coating.

Abstract: A precursor of a ceramic adhesive suitable for use in a vacuum, thermal, and microgravity environment. The precursor of the ceramic adhesive includes a silicon-based, preceramic polymer and at least one ceramic powder selected from the group consisting of aluminum oxide, aluminum nitride, boron carbide, boron oxide, boron nitride, hafnium boride, hafnium carbide, hafnium oxide, lithium aluminate, molybdenum silicide, niobium carbide, niobium nitride, silicon boride, silicon carbide, silicon oxide, silicon nitride, tin oxide, tantalum boride, tantalum carbide, tantalum oxide, tantalum nitride, titanium boride, titanium carbide, titanium oxide, titanium nitride, yttrium oxide, zirconium, diboride, zirconium carbide, zirconium oxide, and zirconium silicate. Methods of forming the ceramic adhesive and of repairing a substrate in a vacuum and microgravity environment are also disclosed, as is a substrate repaired with the ceramic adhesive.

Abstract: A matrix powder for forming a matrix bit body, the matrix powder essentially consisting of a plurality of carbide particles having a particle size distribution of ±20% of a median particle size; and a plurality of metal binder particles is disclosed.

Abstract: A sintered body for a magnetic head slider, which can reduce differences in level of an air bearing surface while yielding a high strength, a magnetic head slider using the same, and a method of manufacturing a sintered body for a magnetic head slider are provided. The sintered body of the present invention is a sintered body comprising alumina crystal grains and a thin film containing carbon provided at a grain boundary between the alumina crystal grains, whereas the alumina crystal grains have an average particle size of 0.05 to 0.5 ?m.

Abstract: High-density components and products as well as processes for making high-density components and products are disclosed. One exemplary component, among others, includes a boron carbide component comprised of a homogeneous boron carbide powder. The component has at least a 93% relative density (RD) and a Vickers hardness of at least 2000 kg/mm2.

Abstract: Multimodal cermet compositions having lower melting point metal binders and methods of making are provided. The multimodal cermet compositions having a low melting point metal binder include: a) a ceramic phase, and b) a low melting point metal binder phase, wherein the ceramic phase is a metal boride with a multimodal distribution of particles, wherein the metal of the metal boride is chosen from Group IV, Group V, Group VI elements of the Long Form of the Periodic Table of Elements, and mixtures thereof, and wherein the low melting metal binder phase is represented by the formula (DEF), wherein D is a base metal chosen from Fe, Ni, Co, Mn and mixtures thereof, E is an alloying metal comprising Cr, Si, and B, and F is an alloying element chosen from C, N, P, Al, Ga, Ge, As, In, Sn, Sb, Pb, Sc, La, Y, Ce, Ti, Zr, Hf, V, Nb, Ta, Mo, W, Re, Ru, Rh, Ir, Pd, Pt, Cu, Ag, Au and mixtures thereof, and wherein said low melting metal binder phase has a melting point less than 1250° C.

Abstract: The compressive strength of a boron carbide sintered compact is improved by controlling crystals of the boron carbide to a polycrystalline structure having a grain size distribution in which coarse crystals with a grain size of 20 ?m or more and fine crystals with a grain size of 10 ?m or less are mixed in an appropriate ratio. Furthermore, a protective member having an improved compressive strength can be provided using the boron carbide sintered compact having a polycrystalline structure in which coarse crystals and fine crystals are mixed in an appropriate ratio or a boron carbide sintered compact containing graphite and silicon carbide.

Abstract: A method of making a sintered ceramic composition includes the steps of: providing a powder that includes at least 50 wt. % boron carbide and 0.05 wt. % to 30 wt. % of at least one oxide selected from oxides of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy Ho, Er, Tm, Yb, and Lu; milling the powder to form a milled powder; drying the milled powder to form a milled, dried powder; and consolidating the milled, dried powder at a temperature in the range of 1500° C. to 2200° C. to form a sintered ceramic composition having a density of at least 90% of theoretical density, the sintered ceramic composition including zirconium diboride in an amount in the range of 1 wt. % to 10 wt. %.

Abstract: A binder-free ceramic feedstock composition for thermal spraying on a surface of an article is provided. The composition comprises: an oxide ceramic powder and a boride and/or carbide ceramic powder. The boride and/or carbide ceramic powders are comprised of micron-sized particles, and the volume content of the oxide ceramic powder is in the range of about 1 to about 85 percent. A method for preparing the binder-free ceramic feedstock and a coated article by a thermal spraying process are also provided.

Abstract: A composite article includes a substrate and a protective layer on the substrate. The protective layer includes a non-oxide ceramic matrix and a refractory phase within the non-oxide ceramic matrix.

Abstract: Components of semiconductor processing apparatus are formed at least partially of erosion, corrosion and/or corrosion-erosion resistant ceramic materials. Exemplary ceramic materials can include at least one oxide, nitride, boride, carbide and/or fluoride of hafnium, strontium, lanthanum oxide and/or dysprosium. The ceramic materials can be applied as coatings over substrates to form composite components, or formed into monolithic bodies. The coatings ca protect substrates from physical and/or chemical attack. The ceramic materials can be used to form plasma exposed components of semiconductor processing apparatus to provide extended service lives.

Abstract: The invention relates to a sintered material which is based on transition metal diborides and comprises a) as main phase, 90-99% by weight of a fine-grained transition metal diboride or transition metal diboride mixed crystal comprising at least two transition metal diborides or mixtures of such diboride mixed crystals or mixtures of such diboride mixed crystals with one or more transition metal diborides, where the transition metals are selected from sub-groups IV to VI of the Periodic Table, b) as second phase, 1-5% by weight of particulate boron carbide and/or silicon carbide and c) optionally as third phase, up to 5% by weight of a non-continuous, oxygen-containing grain boundary phase.

Abstract: Components of semiconductor processing apparatus axe formed at least: partially of erosion, corrosion and/or corrosion-erosion resistant ceramic materials. Exemplary ceramic materials can include at least one oxide, nitride, boride, carbide and/or fluoride of hafnium, strontium, lanthanum oxide and/or dysprosium. The ceramic materials can be applied as coatings over substrates to form composite components, or formed into monolithic bodies. The coatings can protect substrates from physical and/or chemical attack. The ceramic materials can be used to form plasma exposed components of semiconductor processing apparatus to provide extended service lives.

Abstract: Methods are disclosed for dispersing a powder mixture of at least one metal carbide powder and at least one cobalt powder in at least one apolar medium with at least one dispersant and, optionally, at least one wetting agent. According to the invention, the dispersant is an effective dispersant for both cobalt and metal carbide surfaces. The invention is particularly useful for powder mixtures with a fine grained cobalt powder and a relatively high cobalt content. The dispersant used is an amphiphilic compound with a branched copolymer structure.

Abstract: Boron carbide ceramics produced by spark sintering methods have more desirable mechanical properties than conventionally produced carbides. The boron carbide ceramics include amorphous boron, amorphous carbon, and Al2O3 powder as a sintering aid. The boron carbides may also contain a carbon nano fiber in a nearly homogeneously dispersed state. The sintered compact has a relative density of a boron carbide ceramic of approximately not less than 99%. The boron carbide ceramics are prepared preferably by subjecting a mixed powder of the starting raw materials and the carbon nano fiber to simultaneous synthesis and sintering using the spark plasma sintering method.

Abstract: Disclosed is a cemented carbide comprising 5 to 10 mass % of cobalt and/or nickel, and 0 to 10 mass % of at least one selected from a carbide (except for tungsten carbide), a nitride and a carbonitride of at least one selected from the group consisting of metals of groups 4, 5 and 6 of the Periodic Table, the balanced amount of tungsten carbide, a hard phase comprising mainly tungsten carbide particles, and containing ? particles of at least one selected from the carbide, the nitride and the carbonitride, and the hard phase being bonded through a binder phase comprising mainly cobalt and/or nickel, wherein a mean particle size of the tungsten carbide particles is 1 ?m or less, and the cemented carbide having a sea-island structure in which plural binder-phase-aggregated portions composed mainly of cobalt and/or nickel are scattered in the proportion of 10 to 70 area % based on the total area on the surface of the cemented carbide. The cemented carbide is excellent in wear resistance and fracture resistance.

Abstract: A method for producing a nanostructured cermet material, including the steps of preparing an aqueous solution mixture of precursor compounds of the cermet material, introducing the solution mixture into a heated tubular reactor in the form of a fine-particle aerosol, and processing the solution mixture in the heated tubular reactor to form the nanostructured cermet material. The present invention is further directed to a processing apparatus configured for implementing the present method.

Abstract: Ceramics are made of preceramic paper or board structures in a particular shape previously represented in a paper structure, in which the preceramic papers or boards have a content of ceramic fillers between 30 and 95 wt-%, with the ceramic fillers having a particle size <30 ?m. A method for manufacturing such ceramics and the use thereof are also provided.

Abstract: Disclosed is a highly-pure fine titanium carbide powder having a maximum particle size of 100 nm or less and containing metals except titanium in an amount of 0.05 wt % or less and free carbon in an amount of 0.5 wt % or less. The powder has a NaCl-type crystal structure, and a composition represented by TiCxOyNz, wherein X, Y and Z satisfy the relations: 0.5?X?1.0; 0?Y?0.3; 0?Z?0.2; and 0.5?X+Y+Z?1.0.) The powder is produced by: dissolving an organic substance serving as a carbon source in a solvent to prepare a liquid, wherein the organic substance contains at least one OH or COOH group which is a functional group coordinatable to titanium of titanium alkoxide, and no element except C, H, N and O; mixing titanium alkoxide with the liquid to satisfy the following relation: 0.7???1.

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 120 parts by weight of titanium carbide, and 0.2 to 9 parts by weight of carbon.

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 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.