Abstract: The invention concerns a sintered ceramic component of silicon nitride or sialon suitable as rolling element in a bearing and a manufacturing method for making such ceramic components. The ceramic component has high density and a homogeneous and fine microstructure, giving the component excellent mechanical properties. Manufacturing of the sintered ceramic component by SPS is cost-effective and rapid.

Abstract: The invention provides a vessel for molten metal comprising a vessel body formed of an alumina-silica-based material, and a protective layer formed of a silicon nitride- alumina-based material provided on the inner surface of the vessel body, wherein the material for the vessel body is adjusted to have an alumina content x of 72 to 95 parts by weight per 100 total parts by weight of alumina and silica, and the material for the protective layer is adjusted to have a silicon nitride content y per 100 total parts by weight of silicon nitride and alumina in such a manner that y applies to the following formulae: (1) y<?1.1x+128 and (2) y>?0.5x+62.5. The present invention provides a vessel for molten metal having excellent durability and corrosion resistance against hot molten metal.

Abstract: A duplex eutectic silicon alloy including 30-70 weight % silicon, 10-45 weight % nitrogen, 1-40 weight % aluminum, and 1-40 weight % oxygen has a eutectic structure comprising a ??-sialon phase and an ??-sialon phase. The alloy is produced by controlling cooling at a rate of 50° C. or less per minute in combustion synthesis. A ductile sintered product capable of replacing steel in various applications can be produced by placing a compact composed of a powder of the alloy in a sintering furnace which can supply a heat quantity at least ten times the heat capacity of the compact; and sintering the compact at a pressure at least as great as atmospheric pressure, within a nitrogen atmosphere in which the silicon gas mole fraction is 10% or more, and at a temperature within the range from 1400° C. to 1700° C.

Abstract: The invention relates to a powder comprising more than 70% of refractory particles, in weight percent relative to the weight of the powder, a particle of said powder being classed in the fraction called “matrix” or in the fraction called “aggregate”, according to whether it is smaller than, or equal to 100 ?m, or larger than 100 ?m, respectively, said powder comprising, in weight percent relative to the weight of the powder: between 0.1% and 18% of particles of a heat-activatable binder, called “heat-activatable binder particles”; and more than 40% of refractory particles, called “ATZ particles”, having the following chemical composition, in weight percentages on the basis of the oxides of said ATZ particles: 10%?Al2O3?55%; 35%?TiO2?80%; 1%?MgO+Cr2O3?10%; 8%?ZrO2?20%; SiO2?8%.

Abstract: Preparation for producing refractory materials, characterized in that it comprises one or more particulate, refractory components and one or more binders, where—the particulate, refractory component has a mean particle diameter of >0.3 m and—the binder is selected from among—from 0.05 to 50% by weight of a very finely particulate binder having a mean particle diameter of from 10 nm to 0.3 m selected from the group consisting of aluminum oxide, titanium dioxide, zirconium dioxide and/or mixed oxides of the abovementioned oxides, —from 0 to 20% by weight of an inorganic binder, from 0 to 20% by weight of a hydraulically setting binder, —from 0 to 15% by weight of an organic, silicon-free binder—and the preparation additionally contains from 0 to 35% by weight of water, where—the proportion of the particulate, refractory component is equal to 100 and the percentages of the further materials in the preparation are based on the particulate component.

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: A composite material (M) comprising: at least 75% by volume of a mixed electronic conductor compound oxygen anions O<2->(C1) selected from doped ceramic compounds which, at the temperature of use, are present in the form of a crystalline network having ion oxide lattice vacancies and, more particularly, in the form of a cubic phase, a fluorite phase, a perovskite phase, of the aurivillius variety, a Brown-Millerite phase or a pyrochlore phase; and 0.01%-25% by volume of a compound (C2) which is different from compound (C1), selected from oxide-type ceramic materials, non-oxide type ceramic materials, metals, metal alloys or mixtures of said different types of material; and 0%-2.5% by volume of a compound (C3) produced from at least one chemical reaction represented by the equation: xFC1+yFC2 - - - >zFC3, wherein FC1, FC2 and FC3 represent the raw formulae of compounds (C1), (C2) and (C3) and x, y and z represent rational numbers above or equal to 0.

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 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: It is aimed at providing an oxynitride powder, which is suitable for usage as a phosphor, is free from coloration due to contamination of impurities, and mainly includes a fine ?-sialon powder. An oxynitride powder is produced by applying a heat treatment in a reducing and nitriding atmosphere, to a precursor compound including at least constituent elements M, Si, Al, and O (where M is one element or mixed two or more elements selected from Li, Mg, Ca, Sr, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), thereby decreasing an oxygen content and increasing a nitrogen content of the precursor.

Abstract: A nitride glass with the general formula ?x?y?z is provided wherein ? is a glass modifier comprising at least one electropositive element. ? comprises Si, B, Ge, a and/or Al. ? is N or N together with O, whereby the atomic ratio of O:N is in the interval from 65:35 to 0:100.

Abstract: The present invention relates to a method of manufacturing a ceramic cutting insert, based on an oxide ceramic or a nitride ceramic or a mixed ceramic material, possibly containing whiskers, in a process comprising the powder metallurgical steps of providing a ready-to-press ceramic powder, pressing the ready-to-press powder into a compact of desired shape, sintering the compact to dense a ceramic blank followed by tumbling the ceramic blank, to remove sinter skin and provide an edge rounding.

Abstract: The present invention relates to a ceramic material consisting of ?-sialon (Si6-zAlzOzN), polytype 12H, an intergranular amorphous or partly crystalline phase, and containing yttrium with a z-value of from about 0.7 to less than about 1.5. The ceramic material is useful as cutting tool insert for machining of heat resistant super alloys, with good notch wear, acceptable flank wear and sufficient toughness.

Abstract: A method for improving surface thermal shock resistance of a member made of ceramics to which thermal shock resistance is required comprising, forming homogeneously distributed linear dislocation structure on the surface of the member made of ceramics to which thermal shock resistance is required by blasting abrasives composed of fine particles whose average particle size is from 5 ?m to 200 ?m and whose surface shape is convex, wherein Vickers hardness (HV) of said fine particles is 800 or more and equal to or less than the hardness of the member made of ceramics to which thermal shock resistance is required.

Abstract: This invention provides a long-life Sialon insert, the cutting edge of which is resistant to wear and hard to fracture, and a cutting tool equipped with the Sialon insert. Provided are a Sialon insert made of a Sialon sintered body including a Sialon phase comprising an ?-Sialon and a ?-Sialon, and at least one element, originating from a sintering aid, selected from the group consisting of Sc, Y, Dy, Yb, and Lu in an amount of 0.5 to 5 mol % in terms of an oxide thereof, wherein an ?-value, which shows the proportion of the ?-Sialon in the Sialon phase, is from 10% to 40%; the ?-Sialon has a value of Z from 0.2 to 0.7 wherein Z is a variable of the formula Si6-ZAlZOZN8-Z and within a range: 0<Z?4.2; and the sintered body has an average thermal expansion coefficient of 3.5×10?6/K or less at temperatures of room temperature to 1000° C., and a thermal conductivity of 10 W/m·K or more at temperatures of room temperature to 1000° C., and a cutting tool comprising a holder equipped with the Sialon insert.

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 conductive silicon nitride composite sintered body having an average grain size of 100 nm or less and whose relative roughness (Ra) after electric discharge machining is 0.3 ?m or less can be obtained by grinding/mixing a silicon nitride powder and a metal powder together until the average particle size of the silicon nitride powder becomes 30 nm or less, and subsequently by molding and sintering. It is preferable that the crushing/mixing is continued until it is apparent that a peak of added metal in an X-ray diffraction pattern has disappeared during the crushing/mixing.

Abstract: A SiAlON material that includes a two phase composite of an alpha prime SiAlON phase and a beta prime SiAlON phase. The alpha prime phase contains ytterbium. The alpha prime SiAlON phase being present in an amount between about 25 weight percent and about 85 weight percent of the two phase composite. The SiAlON material further includes an intergranular phase.

Abstract: An oxynitride phosphor activated by a rare earth element, represented by the formula CaxSi12−(m+n)Al(m+n)OnN16−n: EuyDyz, wherein stabilizing metal (Ca) is substituted partially by Eu or Eu and Dy where 0.3<x<1.5, 0.01<y<0.7, 0≦z<0.1, 0.6<m<3.0 and 0<n<1.5.

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: The invention relates to a ceramic material in powder form comprising particles having an average particle size of 0.1 to 30 &mgr;m and each formed of an agglomerate of grains with each grain comprising a nanocrystal of a ceramic material of formula (I): Si3-xAlxOyNz, wherein 0≦x≦3, 0≦y≦6 and 0≦z≦4, with the proviso that when x is 0 or 3, y cannot be 0. The ceramic material in powder form according to the invention is suitable for use in the production of ceramic bodies by powder metallurgy, as well as in the formation of heat-resistant coatings by thermal deposition. The ceramic bodies and coatings obtained have improved resistance to thermal shocks.

Abstract: Blocks of material are prepared in a variety of shapes and sizes to be used in the fabrication of models for dental restorations. The material comprises a partially sintered ceramic material. The blocks are used to manufacture molds using CAD/CAM methods and equipment. The molds are useful in the manufacture of dental restorations using ceramics, metals, alloys, or powders thereof, and composite materials. The models milled from the blanks may be used to manufacture a variety of dental restorations including, but not limited to, crowns, bridges, space maintainers, tooth replacement appliances, orthodontic retainers, dentures, posts, jackets, inlays, onlays, facings, veneers, facets, implants, abutments, splints, partial crowns, teeth, cylinders, pins, and connectors.

Abstract: An illumination unit having at least one LED as light source, the LED emitting primary radiation in the range from 300 to 430 nm, this radiation being completely converted into longer-wave radiation by phosphors which are exposed to the primary radiation of the LED, in which unit the conversion takes place at least with the aid of a phosphor which emits green with a peak emission wavelength at 495 to 540 nm and which originates from the class of the Ce-activated sialons, the sialon corresponding to the formula Mp/2Si12−p−qAlp+qOqN16−q:Ce3+, where M=Ca individually or in combination with Sr, with q=0 to 2.5 and p=0.5 to 3.

Abstract: A sialon type phosphor in the form of a powder comprising at least 40 wt % of &agr;-sialon represented by the formula (Cax,My)(Si,Al)12(O,N)16 (where M is at least one metal selected from the group consisting of Eu, Tb, Yb and Er, 0.05<(x+y)<0.3, 0.02<x<0.27 and 0.03<y<0.3) and having a structure such that Ca sites of Ca-&agr;-sialon are partially substituted by other metal M, at most 40 wt % of &bgr;-sialon, and at most 30 wt % of unreacted silicon nitride.

Abstract: A high pressure phase spinel type sialon represented by the chemical formula Si6−xAlxOxN8−x (0<x≦4.2), and a high pressure phase spinel type silicon oxynitride represented by the chemical formula Si3+xO2xN4 (═Si3N4.xSiO2, 0<x<1). Methods for their production by instantaneous pressing by means of an impulse wave.

Abstract: The invention relates to cast parts which contain at least 87 wt. % silicon nitride and up to 13 wt. % of an additive combination comprised of Al2O3 and Y2O3. The initial composition of the mass formulation starts with Y2O3/Al2O3 ratios of less than 1.1, preferably with Y2O3 Al2O3 ratios of 0.2 to 1.09. 1% to 20% of the Y2O3 portion can thus be substituted by an additional element of the group IVb of the periodic table or by the oxide thereof. The cast parts can comprise up to 1.0 wt. % HfO2 and/or ZrO2. Said cast parts preferably have a thickness >98% of the theoretic thickness. At room temperature, the bending strength of the inventive cast parts amounts to ≧1100 MPa and amounts to ≧850 MPa at 1000° C. The inventive cast parts correspond to the formula Si6−zAlzOzN8−z. The degree of substitution z thus amounts to 0.20 to 0.60, preferably from 0.22 to 0.54, especially from 0.3 to 0.35.

Abstract: In ceramic sinter consisting of at least one kind selected from a group consisting of silicon nitride, zirconia, silicon carbide, cermet, SIALON, aluminum nitride and alumina, wear resistant member and electronic component member using thereof, skewness at a contact surface of the ceramic sinter is set at −2 or more and 0 or less, a depth of a micro-crack is set at 5 &mgr;m or less, and in the depth of up to 500 &mgr;m from the surface an area that pores occupy does not exceed 5%. The ceramic sinter as described above can suppress wear of the opponent member. Further, in such ceramic sinter, bonding strength with an element or a metal plate can be heightened to enable to suppress peeling. The electronic components of high reliability can be fabricated accordingly. The present wear resistant member is suitable for sliding member that is used in portions where wear is particularly remarkable.

Abstract: A dry refractory composition having superior insulating value. The dry refractory composition also may have excellent resistance to molten metals and slags. The composition includes filler lightweight material, which may be selected from perlite, vermiculite, expanded shale, expanded fireclay, expanded alumina silica hollow spheres, bubble alumina, sintered porous alumina, alumina spinel insulating aggregate, calcium alumina insulating aggregate, expanded mulllite, cordierite, and anorthite, and matrix material, which may be selected from calcined alumina, fused alumina, sintered magnesia, fused magnesia, silica fume, fused silica, silicon carbide, boron carbide, titanium diboride, zirconium boride, boron nitride, aluminum nitride, silicon nitride, Sialon, titanium oxide, barium sulfate, zircon, a sillimanite group mineral, pyrophyllite, fireclay, carbon, and calcium fluoride.

Abstract: Molybdenum disilicide/&bgr;′-Si6−zAlzOzN8−z, wherein z=a number from greater than 0 to about 5, composites are made by use of in situ reactions among &agr;-silicon nitride, molybdenum disilicide, and aluminum. Molybdenum disilicide within a molybdenum disilicide/&bgr;′-Si6−zAlzOzN8−z eutectoid matrix is the resulting microstructure when the invention method is employed.