Abstract: There are provided a cubic boron nitride sintered body having a surface also excellent in adhesiveness to a ceramic coating film, while having excellent wear resistance and defect resistance, and a manufacturing method thereof, and a tool. The cubic boron nitride sintered body of the present invention includes 60.0 to 90.0% by volume of cubic boron nitride, the remainder being a binder phase, wherein the binder phase contains: at least any of a nitride, a boride, and an oxide of Al; at least any of a carbide, a nitride, a carbonitride, and a boride of Ti; and a compound represented by the following formula (1): W2NixCo(1-x)B2(0.40?x<1)??(1).

Abstract: To provide a hexagonal boron nitride powder which contains agglomerates, has a maximum torque calculated by measuring in accordance with JIS-K-6217-4 of 0.20 to 0.50 Nm, a DBP absorption rate of 50 to 100 ml/100 g, a tap bulk density of 0.66 to 0.95 g/cm3 and reduced anisotropy of heat conduction and can provide high heat conductivity and dielectric strength to a resin composition produced by filling a resin therewith and a process for producing the powder by carrying out a reduction nitriding reaction using boron carbide.

Abstract: A cubic boron nitride sintered material includes: more than 80 volume % and less than 100 volume % of cubic boron nitride grains; and more than 0 volume % and less than 20 volume % of a binder phase. The binder phase includes: at least one selected from a group consisting of a simple substance, an alloy, and an intermetallic compound selected from a group consisting of a group 4 element, a group 5 element, a group 6 element in a periodic table, aluminum, silicon, cobalt, and nickel. A dislocation density of the cubic boron nitride grains is more than or equal to 1×1015/m2 and less than or equal to 1×1017/m2.

Abstract: A sintered material includes a first phase and a second phase, wherein the first phase is composed of cubic boron nitride particles, and the following relational expressions are satisfied when more than or equal to two cubic boron nitride particles adjacent to and in direct contact with each other among the cubic boron nitride particles are defined as a contact body, Di represents a length of an entire perimeter of the contact body, n represents the number of contact locations at which the cubic boron nitride particles are in direct contact with each other, dk represents a length of each of the contact locations, and ?dk (where k=1 to n) represents a total length of the contact locations: Dii=Di+(2×?dk (where k=1 to n)); and [(Dii?Di)/Dii]×100?50.

Abstract: Implementations disclosed herein generally provide a lift pin that can improve the deposition rate and uniform film thickness above lift pin areas. In one implementation, the lift pin includes a first end coupling to a shaft, the first end having a pin head, and the pin head having a top surface, wherein the top surface is planar and flat, and a second end coupling to the shaft, the second end having a flared portion, wherein the flared portion has an outer surface extended along a direction that is at an angle of about 110° to about 140° with respect to a longitudinal axis of the lift pin.

Abstract: The present application is a new improvement in the fine-grained cubic Boron Nitride sintered compact which may be employed to manufacture a cutting tool. The compact contains at least 80 vol % cBN and is sintered under HPHT conditions. The invention has lower levels of unreacted cobalt in the final sintered material than conventions materials. The invention has proved beneficial in the machining of ferrous metal alloys such as sintered metal alloys.

Abstract: A method for producing a composite of cubic boron nitride dispersed in a SiAlON ceramic. This method involves mixing silicon nitride nanoparticles, aluminum nitride nanoparticles, silica nanoparticles, calcium oxide nanoparticles, and cubic boron nitride microparticles to produce a mixture. The cubic boron nitride may be coated with nickel. The mixture is sintered to produce the composite, and this sintering may involve spark plasma sintering and/or sintering at a relatively low temperature. The composite may comprise a mixture of Ca-?-SiAlON and ?-SiAlON ceramic reinforced by boron nitride in either or both cubic and hexagonal phases.

Abstract: A surface-coated boron nitride sintered body tool is provided, in which a cutting edge portion includes a compound sintered body and a coating layer. The compound sintered body includes cBN particles. The compound sintered body includes 45-80 vol % of cBN particles. A first particle size distribution curve of the cBN particles has one or more peaks in a range in which a particle size is 0.1-0.7 ?m. A second particle size distribution curve of the cBN particles has a first peak having a maximum peak height in a range in which the particle size is 2.0-7.0 ?m. An integral value ratio (Io/It×100) is 1-20, in the second particle size distribution curve, the integral value Io being in the range in which the particle size is 0.1-0.7 ?m, and the integral value It being in an entire range.

Abstract: The invention relates to boron nitride agglomerates, comprising lamellar, hexagonal boron nitride primary particles, which are agglomerated with one another with a preferred orientation, the agglomerates formed being flake-shaped. The invention also relates to a method for producing said boron nitride agglomerates, characterized in that lamellar, hexagonal boron nitride primary particles are agglomerated in such a way that they line up with one another with a preferred orientation. The flake-shaped agglomerates according to the invention are suitable as filler for polymers for making polymer-boron nitride composites and for hot pressing of boron nitride sintered compacts.

Abstract: Solid structures for thermal management are provided. In one aspect, the solid structures can comprise a metal-ceramic composite member assembled to be in thermal contact with a heat source. The metal-ceramic composite member can be mechanically coupled to an assembly (e.g., an electronic assembly) containing the heat source, and can provide mechanical stability to such assembly. In another aspect, the solid structures can comprise an oxide member that covers a surface of the metal-ceramic composite member, forming a metal-ceramic-oxide interface at the surface. The thickness of the oxide member combined with the magnitude of its thermal conductivity relative to the thermal conductivity of the metal-ceramic composite member can permit heat transport substantially along a direction substantially parallel to the metal-ceramic-oxide interface, and can reduce heat transfer through such interface.

Abstract: A horizontal continuous caster includes a tundish supporting a quantity of molten metal together with a cooled mold and conventional casting movement apparatus. The interface between the cooled mold and the tundish is provided by an improved tundish nozzle having a fabrication which locates the contact area between the nozzle and the cooled mold surfaces to the nozzle periphery thereby locating heat transfer between the mold and the molten metal within the tundish nozzle at the outer portion of the nozzle. The nozzle structure creates peripheral contact area and insulative air spaces between the nozzle and mold surfaces. The improved insulative properties of the nozzle construction in turn facilitates the use of higher strength, longer wear materials for the tundish nozzle.

Abstract: A cBN sintered body tool has the following feature. In at least one cross sectional surface of the cBN sintered body tool taken along a plane perpendicular to a joining surface having the largest area in joining surfaces between the cBN sintered body and the joining layer, a point C and a point D are assumed to represent points away by ¼ of the length of a line segment connecting a point A and a point B shown in a figure. A value obtained when an area of a region surrounded by a line segment connecting the point C and the point D, the first cBN particle, the second cBN particle, and the binder phase is divided by the length of the line segment connecting the point A and point B to each other is 0.14-0.6 ?m.

Abstract: A cubic boron nitride sintered body tool has, at least at a cutting edge, a cubic boron nitride sintered body composed of a cubic boron nitride particle and a binder phase. The binder phase contains at least Al2O3 and a Zr compound. On any straight line in the sintered body, the mean value of a continuous distance occupied by Al2O3 is 0.1-1.0 ?m, and the standard deviation of the continuous distance occupied by Al2O3 is not more than 0.8. On the straight line, X/Y is 0.1-1 where X represents the number of points of contact between Al2O3 and the Zr compound, and Y represents the sum of the number of points of contact between Al2O3 and cBN and the number of points of contact between Al2O3 and binder phase component(s) other than Al2O3 and the Zr compound.

Abstract: A gettered polycrystalline group III metal nitride is formed by heating a group III metal with an added getter in a nitrogen-containing gas. Most of the residual oxygen in the gettered polycrystalline nitride is chemically bound by the getter. The gettered polycrystalline group III metal nitride is useful as a raw material for ammonothermal growth of bulk group III nitride crystals.

Abstract: It is an object of the present invention to provide a sintered cBN compact having excellent wear resistance and fracture resistance even in machining centrifugally cast iron having a property of being difficult to machine, and to provide a sintered cBN compact tool. A sintered cBN compact of the present invention contains 20% by volume or more and 65% by volume or less of cBN and, as a binder, 34% by volume or more and less than 80% by volume of Al2O3, at least one selected from the group consisting of nitrides, carbides, carbonitrides, borides, and boronitrides of Zr and solid solutions thereof (hereinafter, referred to as “X”), and ZrO2, the total amount of X and ZrO2 being 1.0% by volume or more and 6.0% by volume or less, the volume ratio of ZrO2 to Al2O3, ZrO2/Al2O3, being 0.010 or more and less than 0.100, in which the ratio Itetragonal ZrO2(101)/I?Al2O3(110) is 0.

Abstract: A boron nitride composition comprising at least two different boron nitride powder materials having different properties, e.g., surface areas, particle size, tap density, etc.

Abstract: A cubic boron nitride sintered body with excellent wear resistance and fracture resistance. The cubic boron nitride sintered body includes 85 to 95% by volume of cubic boron nitride, and 5 to 15% by volume of a binder phase and inevitable impurities. The binder phase has at least three compounds selected from carbides, nitrides, carbonitrides, oxides and mutual solid solutions thereof of Al, V, Cr, Mn, Co, Ni, Nb and Mo. An amount of an aluminum element contained in the cubic boron nitride sintered body is 0.5 to 5% by mass based on a total mass of the cubic boron nitride sintered body. The binder phase is essentially free of both pure metals and alloys consisting of pure metals.

Abstract: A superhard element (22) for a machine tool, comprising polycrystalline cubic boron nitride (PCBN) material containing whiskers of a ceramic material, the PCBN material comprising at least about 50 volume percent cubic boron nitride (cBN) material dispersed in a binder matrix comprising a compound including titanium and the whiskers; the content of the whiskers being at least 1 weight percent and at most 6 weight percent of the binder matrix.

Abstract: The cubic boron nitride sintered body tool of the present invention has a cubic boron nitride sintered body including cubic boron nitride particles and a binder phase at at least a cutting edge. The cubic boron nitride sintered body includes 40-70 volume % of cubic boron nitride particles. The binder phase includes a first component and a second component. The first component includes TiC, and the second component includes one or both of TiB2 and AlB2. When the X-ray diffraction intensity of plane (200) of the first component is I1 and the X-ray diffraction intensity of plane (101) of said second component is I2, I1 is the maximum of the X-ray diffraction intensity of all components in the cubic boron nitride sintered body excluding the cubic boron nitride particles, and satisfies 0.01?I2/I1?0.1.

Abstract: PCBN material consisting essentially of cubic boron nitride (cBN) grains and binder material, the content of the cBN grains being at least 80 weight percent of the PCBN material; the binder material comprising greater than 50 weight percent Al and a combined content of at least 5 weight percent of an iron group element and a refractory element, the iron group element selected from the group consisting of Co, Fe, Ni and Mn, and the refractory element selected from the group consisting of W, Cr, V, Mo, Ta, Ti, Hf and Zr.

Abstract: A new investment material for the pressing loss wax technique for dental glass ceramics. It has been found that the addition of fillers to a magnesium phosphate investment, specifically metal oxides with elevated melting points ranging from 1800 to 2800° C., provides a protection barrier against the reaction between the high alkaline content of the glass ceramic and the investment during the pressing process in the range of 800 to 950° C. Specifically, it has been found that the addition of aluminum oxide of about 2 to 5 percent of the total dry mix in combination with any of the zirconium oxide, yttrium stabilized zirconium, titanium dioxide and boron nitride in proportions of about 3.5%, enhances the barrier against a surface reaction and improves the thermal properties of the investment.

Abstract: A method for producing a highly uniform and highly dense sintered cubic boron nitride compact having high hardness by sintering at a milder condition without a binder, is provided. The method includes deflocculating secondary particles in cubic boron nitride starting powders by dispersing the starting powders in a solution of a deflocculant; molding the green compact after removing the solution of the deflocculant from the starting powders; and then sintering the green compact in the presence of a supercritical fluid source in a supercritical state by pressing and heating the green compact together with the supercritical fluid source. The supercritical fluid source can be one or more selected from a group consisted of polyvinylidene chloride, polyvinyl chloride, polyethylene, polypropylene, polystyrene, a polyester and an ABS resin. In the sintering, the pressure is 5 GPa or higher, and the temperature is 1400° C. or higher.

Abstract: A sintered cubic boron nitride (cBN) compact for use in a tool is obtained by sintering a mixture of (i) cubic boron nitride, (ii) aluminum oxide, (iii) one or more refractory metal compounds, and (iv) aluminum and/or one or more non-oxide aluminum compounds. The sintered bodies may have sufficient strength and toughness to be used as a tool material in solid, i.e. not carbide supported, form, and may be useful in heavy machining of cast irons.

Abstract: Spherical boron nitride nanoparticles having an average particle diameter of less than 50 nm is obtained by a method of synthesizing spherical boron nitride nanoparticles including the following steps; heating a mixture of boric acid ester and nitrogen gas in ammonia gas and argon gas to form reaction product; crystallizing reaction product to form precursor of spherical boron nitride nanoparticles; and, heating the precursor in inert gas.

Abstract: Provided are a ceramic member being a sintered body including at least forsterite and boron nitride as major components, and in which the boron nitride is oriented in one direction, a probe holder formed by using the ceramic member, and a method for manufacturing the ceramic member. In the ceramic member, the index of orientation preference is equal to or lower than 0.07, and the coefficient of thermal expansion at 20 to 300° C. in a direction parallel to the direction of orientation is (3 to 5)×10?6/° C., or the three-point bending strength based on JIS R 1601 is equal to or higher than 250 MPa.

Abstract: A composite compact formed by sintering, at high temperature/high pressure, a composition including cBN in a range of about 5 to about 60 vol. %, zirconia (or in the range about 5 to about 20 vol. %), and other ceramic material. Subsequent to sintering, the zirconia exists in the cubic phase and/or tetragonal phase. The zirconia may be either stabilized or unstabilized prior to sintering. The other ceramic material may include one or more of nitrides, borides, and carbides of Ti, Zr, Hf, Al, Si, or Al2O3. Some of the ceramic material is formed during the sintering process. The compact can be bonded to a tungsten carbide substrate during the sintering process.

Abstract: The cubic boron nitride sintered body tool of the present invention has a cubic boron nitride sintered body including cubic boron nitride particles and a binder phase at at least a cutting edge. The cubic boron nitride sintered body includes 40-70 volume % of cubic boron nitride particles. The binder phase includes a first component and a second component. The first component includes TiC, and the second component includes one or both of TiB2 and AlB2. When the X-ray diffraction intensity of plane (200) of the first component is I1 and the X-ray diffraction intensity of plane (101) of said second component is I2, I1 is the maximum of the X-ray diffraction intensity of all components in the cubic boron nitride sintered body excluding the cubic boron nitride particles, and satisfies 0.01?I2/I1?0.1.

Abstract: The present invention relates to a hexagonal boron nitride platelet particle having a layer of a ferromagnetic metal between the layers of hexagonal boron nitride thereof, and a process for preparing the composition thereof. The present invention further relates to polymeric composites formed therefrom. The present invention describes improvements in thermal conductivity of said composites when subject to an orienting magnetic field.

Abstract: cBN sintered body includes cBN and a binder phase, wherein a content of the cBN is 82-98 volume %, and in a cross section of the cBN sintered body, an isolated binder phase having an area of 0.05-0.5 ?m2 has a protrusion of two or more steps, and assuming that in a first-step protrusion, A1 represents a side length which is perpendicular in a tip direction, and B1 represents a side length which is parallel in the tip direction; and in a second-step protrusion, A2 represents a side length which is perpendicular in the tip direction, and B2 represents a side length which is parallel in the tip direction, an area ratio of an isolated binder phase having a protrusion in which A1/B1 is 1-10 times of A2/B2, to the whole of the binder phase having the area of 0.05-0.5 ?m2, is 25% or more.

Abstract: The invention generally relates to a sintered CBN composite compact having a non-CBN portion. The compact includes about 86 to about 90% CBN and the non CBN portion contains borides and nitrides of Al. The compact is for use as a cutting tool insert in continuous machining of gray cast iron. The sintered compact has a thermal conductivity of 1.25-4 W/cm/° K. in the temperature range of about 200° C. to about 600° C. and sonic velocity of at least about 14.5 Km/sec at room temperature.

Abstract: The invention relates to a ceramic product, manufactured from a mixture made of natural and/or synthetic inorganic non-metal raw materials, at least one binder and optionally further additives. In order to provide ceramic products allowing for disadvantages known from the prior art to be eliminated, at least with respect to corrosion and erosion, it is proposed that the ceramic products are manufactured from a mixture comprising a) at least 10% by weight (based on the weight of all solids of the mixture) oxidic components, b) 0.05 to 2.7% by weight (based on the weight of all solids of the mixture) at least one organic-based binder, acting as a solubilizer in the mixture, and c) 3 to 10% by weight (based on the weight of all solids of the mixtures) hydrous dispersing agent, and that the ceramic product contains less than 0.1% by weight (based on the total weight of the ceramic product) of carbon after the use thereof at temperatures above 600° C.

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: The present invention provides a slurry for preparing boron nitride aggregates of spherical geometry, comprising: 3 wt %˜25 wt % of boron nitride; 1 wt %˜25 wt % of a nano-ceramic material; and a solvent as a complement to 100 wt %. In comparison with conventional preparation methods, preparation of boron nitride aggregates of spherical geometry at relatively low temperature can be achieved by using the slurry. Therefore, the demands of energy conservation and low cost are fulfilled. Besides, the present invention also provides a method for preparing boron nitride aggregates of spherical geometry.

Abstract: A cubic boron nitride-containing sintered body has heightened fracture resistance and toughness without lowered wear resistance. The body has a binder phase containing titanium nitride and titanium carbonitride, cubic boron nitride and inevitable impurities. A distance between a Bragg angle 2? of a (200) plane diffraction line of titanium carbonitride and a Bragg angle 2? of a (200) plane diffraction line of titanium nitride in an X-ray diffraction measurement using a Cu—K? line is 0.30° or more and 0.60° or less, and a full width at half maximum intensity of the (200) plane diffraction line of titanium carbonitride is 0.30° or more and 0.50° or less.

Abstract: The present invention relates to a cutting tool insert preferably for machining of hardened steel, hot and cold working tool steel, die steel, case hardened steel, high speed steel and ductile grey cast iron and composed of a composite comprising from about 30 to less than about 60 vol-% of a cBN-phase and a binder phase comprising a titaniumcarbonitride phase and a TiB2 phase. According to the invention, in the XRD pattern from the composite using CuK?-radiation the peak height ratio of the strongest TiB2 peak and the strongest cBN peak is less than about 0.02.

Abstract: A sintered cubic boron nitride (cBN) compact for use in a tool is obtained by sintering a mixture of (i) cubic boron nitride, (ii) aluminum oxide, (iii) one or more refractory metal compounds, and (iv) aluminum and/or one or more non-oxide aluminum compounds. The sintered bodies may have sufficient strength and toughness to be used as a tool material in solid, i.e. not carbide supported, form, and may be useful in heavy machining of cast irons.

Abstract: A composition for coating sliding or rolling or fretting or impacting members is formed by preparing a composite powder of TiB2 and BN, with a TiB2 to BN ratio ranging from 1:7 to 20:1, and a metallic matrix selected from the group consisting of nickel, chromium, iron, cobalt, aluminum, tungsten, carbon and alloys thereof.

Abstract: A composite article includes a substrate and a ceramic nanocomposite layer disposed on the substrate. The ceramic nanocomposite layer has a composition that includes silicon, boron, carbon and nitrogen.

Abstract: A sintered cubic boron nitride (cBN) compact for use in a tool is obtained by sintering a mixture of (i) cubic boron nitride, (ii) aluminum oxide, (iii) one or more refractory metal compounds, and (iv) aluminum and/or one or more non-oxide aluminum compounds. The sintered bodies may have sufficient strength and toughness to be used as a tool material in solid, i.e. not carbide supported, form, and may be useful in heavy machining of cast irons.

Abstract: There is provided a hard film excellent in wear resistance. The hard film in accordance with the present invention includes (TiaCrbAlcLd) (BxCyNz) in terms of composition, in which the L is at least one of Si and Y, and the a, b, c, d, x, y, and z each denote the atomic ratio, and satisfy: 0.1?a<0.3; 0.3<b<0.6; 0.2?c<0.35; 0.01?d<0.1; a+b+c+d=1; x?0.1; y?0.1; 0.8?z?1; and x+y+z=1.

Abstract: A sintered cubic boron nitride (cBN) compact for use in a tool is obtained by sintering a mixture of (i) cubic boron nitride, (ii) aluminum oxide, (iii) one or more refractory metal compounds, and (iv) aluminum and/or one or more non-oxide aluminum compounds. The sintered bodies may have sufficient strength and toughness to be used as a tool material in solid, i.e. not carbide supported, form, and may be useful in heavy machining of cast irons.

Abstract: A cubic boron nitride sintered material where wear resistance is suppressed from decreasing having excellent chipping resistance and a cutting tool made thereof are provided. The sintered material is constituted from cubic boron nitride particles that are bound by a binder phase, while the binder phase contains a carbide of at least one kind of metal element selected from among metals of groups 4, 5 and 6 of the periodic table and a nitride of at least one kind of metal element selected from among metals of groups 4, 5 and 6 of the periodic table coexisting therein, and therefore the particles can be suppressed from coming off and the binder phase can be suppressed from wearing and coming off at the same time, thereby making the sintered material having high wear resistance and particularly excellent chipping resistance.

Abstract: A refractory material used in refractory furnace liners, combustion chambers, baffles and artificial fire logs includes alumina silicate; an additive comprising at least one of silicon carbide, silicon nitride, boron carbide, boron nitride and silicon carbo-nitride; and a binder. The refractory material is light weight, has a high noise reduction capacity, is fire resistant and has a reduced silica content. In a most preferred embodiment, the additive makes up 50.0% to 55.0% of the material by weight, the binder makes up 4.5% to 5.0% of the material by weight and the linear shrinkage of the material is no greater than 3.5% at 2600° F. A preferred binder is colloidal silica although many others are suitable. Preferably, the material is free of cellulose fiber and sodium silicate.

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 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 method for producing cubic boron nitride in which hBN is held in the presence of a catalyst substance under conditions in which cBN remains thermodynamically stable, to thereby cause hBN to undergo a phase transition to form cBN, wherein the catalyst substance contains a lithium source, a magnesium source, and a carbon source. The performance of cBN is improved even though phase transition ratio from hBN to cBN is increased.

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 refractory composition having excellent erosion resistance and infiltration resistance to a molten metal and a formed article and a sintered article produced from the refractory composition are provided. The refractory composition comprises for 100 parts by mass of at least one compound selected from the group consisting of silicon nitride, boron nitride, and silicon carbide, 5 to 40 parts by mass of at least one compound selected from the group consisting of calcium fluoride, magnesium fluoride, calcium oxide or its precursor, magnesium oxide or its precursor, barium oxide or its precursor, and barium sulfate. The content of the silicon nitride, boron nitride, and silicon carbide in the composition is 20 mass % or more.

Abstract: The invention generally relates to a sintered CBN composite compact having a non-CBN portion. The compact includes about 86 to about 90% CBN and the non CBN portion contains borides and nitrides of Al. The compact is for use as a cutting tool insert in continuous machining of gray cast iron. The sintered compact has a thermal conductivity of 1.25-4 W/cm/° K. in the temperature range of about 200° C. to about 600° C. and sonic velocity of at least about 14.5 Km/sec at room 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.