Abstract: A SiAlON composite includes a SiAlON phase including ?-SiAlON phase, ?-SiAlON phase and grain boundary phase. The SiAlON composite is prepared from a starting powder mixture including a silicon nitride powder and at least one powder providing aluminum, oxygen, nitrogen, yttrium (Y) and erbium (Er) to the SiAlON composite. The SiAlON composite contains the SiAlON phase of at least 90 vol %, z-value of the ?-SiAlON phase ranges between 0.27 and 0.36 and thermal diffusivity of the SiAlON composite is equal to or greater than 2.4 (mm2/sec) and equal to or less than 5.2 (mm2/sec).

Abstract: An oxynitride phosphor powder is an ?-SiAlON phosphor having a dominant wavelength of 565-577 nm and fluorescence intensity and external quantum efficiency that are high enough for practical use. The oxynitride phosphor powder comprises an ?-SiAlON represented by the compositional formula: Cax1Eux2Ybx3Si12?(y+z)Al(y+z)OzN16?z (wherein 0.0<x1?2.0, 0.0000<x2?0.0100, 0.0000<x3?0.0100, 0.4?x2/x3?1.4, 1.0?y?4.0, 0.5?z?2.0).

Abstract: An outer ring, an inner ring and a ball that are a rolling contact member formed of sintered ? sialon inexpensive and capable of reliably ensuring sufficient durability, is constituted of a sintered body containing ? sialon as a main component and having a remainder formed of an impurity, and the outer ring, the inner ring and the ball have raceway/rolling contact surfaces, i.e., an outer ring raceway surface, an inner ring raceway surface and a ball rolling contact surface included in a portion having an outer ring high density layer, an inner ring high density layer and a ball high density layer higher in density than an inner portion.

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: Industrial blast nozzles are disclosed which have liners made, at least in part, from a SiAlON-containing ceramic material which has a surface resistance of about 12 megaOhms or less and an erosion rate of about 1.9×10?4 cm3/g or less. The SiAlON-containing ceramic material preferably contains a two-phase SiAlON, silicon carbide, and a conductive phase that is one or more of titanium nitride, tantalum nitride, zirconium nitride, and titanium carbide.

Abstract: Composite materials composed of cubic boron nitride (cBN) and a matrix component of various ceramic oxides, nitrides, and solid solutions of matrix materials as well as whisker reinforcements. Methods of manufacture and their use in high performance machining of ferrous metals are also claimed and disclosed.

Abstract: A SiAlON armor ceramic made from a starting powder mixture including silicon nitride powder. The armor ceramic includes a ceramic body that has between about 64 weight percent and about 90 weight percent alpha SiAlON phase that contains an alpha SiAlON-bound rare earth element. The ceramic body also has between about 5 weight percent and about 35 weight percent of a beta SiAlON phase of the formula Si6?zAlzOzN8?z wherein the value of “z” ranges between about 0.10 and about 0.35. The alpha SiAlON-bound rare earth element in the alpha SiAlON phase is present as a result of the starting powder mixture that contains between about 1 weight percent and about 7 weight percent of an oxide of the alpha SiAlON-bound rare earth element. The ceramic body has a fracture toughness (KIC) greater than about 6.00 MPa·m1/2 and a Vickers hardness (HVN) equal to greater than about 19.3 GPa.

Abstract: A SiAlON armor ceramic made from a starting powder mixture including silicon nitride powder. The armor ceramic includes a ceramic body that has between about 64 weight percent and about 90 weight percent alpha SiAlON phase that contains an alpha SiAlON-bound rare earth element. The ceramic body also has between about 5 weight percent and about 35 weight percent of a beta SiAlON phase of the formula Si6?zAlzOzN8?z wherein the value of “z” ranges between about 0.10 and about 0.35. The alpha SiAlON-bound rare earth element in the alpha SiAlON phase is present as a result of the starting powder mixture that contains between about 1 weight percent and about 7 weight percent of an oxide of the alpha SiAlON-bound rare earth element. The ceramic body has a fracture toughness (KIC) greater than about 6.00 MPa·m1/2 and a Vickers hardness (HVN) equal to greater than about 19.3 GPa.

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: A cutting insert 1 is made of an aluminum oxide-based composite sintered body constituted by a ternary ceramic material including aluminum oxide, silicon carbide, and a sialon. The sialon in the aluminum oxide-based composite sintered body is Si—Al—O—N as defined by JCPDS No. 32-0026 in X-ray diffraction analysis.

Abstract: A SiAlON ceramic armor made from a starting powder mixture. The ceramic armor contains between about 60 weight percent and about 98 weight percent alpha SiAlON phase that contains an alpha SiAlON-bound rare earth element and between about 2 weight percent and about 40 weight percent of a beta SiAlON phase of the formula Si6?zAlzOzN8?z wherein the value of “z” ranges between about 0.2 and about 1.0. The ceramic armor further comprising sintering aid residue present as a result of the starting powder mixture containing between about 4 weight percent and about 14 weight percent of an oxide of an alpha SiAlON-bound rare earth element. The ceramic armor has a fracture toughness (KIC) greater than about 6.00 M·Pa m1/2 and a Vickers hardness (HVN) equal to greater than about 17.5 GPa.

Abstract: A silicon nitride sintered body comprising ?-sialon expressed by a composition formula of Si6?ZAlZOZN8?Z, wherein z value being the dissolved amount is 0.1 to 1, as a main phase, a grain boundary phase and Fe silicide particles. The grain boundary phase contains RE (Group III elements in the periodic table)-Al—Si—O, and component ratios of Al, Si and RE in terms of Al2O3, SiO2, RE2O3, respectively is 5 to 50 mass % of Al2O3, 5 to 20 mass % of SiO2, and the balanced amount of RE2O3, the grain boundary phase is contained in a range of 20 volume % or less to 100 volume % of the sintered body, and the Fe silicide particles is contained in 0.02 to 3 mass % in terms of Fe to 100 mass % of the sintered body. Its high thermal shock resistance provides suitable applications to members for molten metal, hot working, and digging.

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 provides a method of synthesizing a Si/C/N/Ea/Fb/Gc/O multielement nanopowder that is directly suitable for sintering, E, F, and G representing three distinct metallic elements other than Si, and at least one of a, b, and c being non-zero. The nanopowder is obtained by laser pyrolysis of an aerosol comprising at least one metal precursor, hexamethyldisilazane Si2C6NH19 used as the sole solvent for said at least one metal precursor, and silane SiH4. Each grain of the resulting nanopowder contains all of the elements Si, C, N, Ea, Fb, Gc, and O, and the chemical composition of the nanopowder in terms of equivalent stoichiometric compounds is such that its free carbon content is less than 2% by weight and its SiO2 content is less than 10% by weight. The use of this nanopowder for fabricating a Si3N4/SiC composite ceramic.

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: 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 material based on SiAlON contain 70-97 vol. % of alpha and beta-SiAlON and an amorphous or partially crystalline grain boundary phase and 3 to 30 vol.% of a hard material. The material has an alpha-SiAlON gradient which decreases from the outside to the inside.

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: 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 SiAlON ceramic body made from a starting powder mixture that includes silicon nitride powder and one or more powders that provide aluminum, oxygen, nitrogen, and two selected rare earth elements to the SiAlON ceramic body wherein the selected rare earth elements are selected from at least two groups of the following three groups of rare earth elements wherein Group I comprises La, Ce, Pr, Nd, Pm, Sm and Eu, and Group II comprises Gd, Tb, Dy and Ho, and Group III comprises Er, Tm, Yb and Lu. The SiAlON ceramic body includes a two phase composite that includes an alpha prime SiAlON phase and a beta prime SiAlON phase wherein the alpha prime SiAlON phase contains one or more of the selected rare earth elements excluding La and Ce. The silicon nitride powder makes up at least about 70 weight percent of the starting powder mixture wherein the beta-silicon nitride content of the silicon nitride powder has a lower limit equal to zero weight percent and an upper limit equal to about 1.

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 method of making a SiAlON ceramic body that includes a two phase composite comprising an alpha prime SiAlON phase and a beta prime SiAlON phase, the method includes the steps of: providing a starting powder that comprises at least about 70 weight percent silicon nitride powder and one or more other powders that provide aluminum, oxygen, nitrogen, and at least two selected rare earth elements to the SiAlON ceramic body wherein the rare earth elements are selected from at least two groups of the following three groups of rare earth elements wherein Group I comprises La, Ce, Pr, Nd, Pm, Sm and Eu, and Group II comprises Gd, Tb, Dy and Ho, and Group III comprises Er, Tm, Yb and Lu; and consolidating the starting powder mixture to form a ceramic body comprising a two phase composite comprising an alpha prime SiAlON phase and a beta prime SiAlON phase, and the alpha prime SiAlON phase containing one or more of the selected rare earth elements excluding La and Ce, and the ceramic body having a composition falling

Abstract: Ceramic plates for side dams of twin-drum continuous strip casters comprising a REAG phase of 10 to 90 vol. %, a Sialon phase of 5 to 50 vol. %, a BN phase of 5 to 50 vol. % and an amorphous phase of over 0 to 20 vol. %, with the REAG phase comprising at least one rare-earth aluminum garnet phase selected from YAG, ErAG, YbAG and DyAG phases and the Sialon phase having a chemical formula, Si6?zAlzOzN8?z, wherein Z is between 0.05 and 1.9.

Abstract: The present invention consists of a synergistic mixture of Si3N4, Al2O3, AlN, SiO2 and Nd2O3. The cost effective synergistic composition is useful for the preparation of dense neodymium stabilised ?-Si3N4-?-SiAlON composite of the order of >98% theoretical density, having high hardness and high fracture toughness. The dense ?-Si3N4-?-SiAlON composite will be useful for low temperature applications as wear parts like bearing and roller materials and particularly for grinding and milling operations like grinding balls.

Abstract: The present invention provides a process for the manufacture of dense neodymium stabilized ?-Si3N4-?-SiAlON composite, wherein a synergistic composition essentially consisting of Si3N4, Al2O3, AlN, SiO2 and Nd2O3 as starting materials is mixed in proportion to make a total of 100 mole in the mixed batch, passing the powder through 100 mesh, pressing the powder to form green compacts, sintering the green compacts at a temperature in the range of 1700° to 1900° C. in nitrogen atmosphere. The process of the present invention provides neodymium stabilized ?-Si3N4-?-SiAlON composites by processing a composition from the system Si3N4—Al2O3.AlN—Nd2O3.9AlN—SiO2 resulting into dense product of the order of >98% theoretical density with the advantages such as cost effectiveness, high hardness and high fracture toughness.

Abstract: A method for making a crystallized ceramic body containing a two phase composite comprising an alpha prime SiAlON phase that contains ytterbium and a beta prime SiAlON phase, the process includes the steps of: blending together a starting powder mixture that upon densification forms the SiAlON ceramic, the starting powder includes at least about 70 weight percent silicon nitride powder wherein the silicon nitride powder contains beta silicon nitride in an amount less than or equal to about 1.

Abstract: This invention is about SiALON ceramics comprising an alpha SiAlON, a beta SiAlON and an intergranular amorphous and/or crystalline phase. Said alpha SiALON phase was prepared from a multi-cationic mixture including the element of calcium, at least one of yttrium and/or a rare earth element with atomic number greater than 62 and at least one of a rare earth element with atomic number equal or smaller than 62. The second phase, beta SiALON contains elements of Si, Al, O, N. The third phase, amorphous and/or crystalline intergranular phase contains in addition to elements of Si, AL, O, N, element of calcium, at least one of yttrium and/or a rare earth element with atomic number greater than 62 and at least one of a rare earth element with atomic number equal or smaller than 62. This material with its toughness, high fracture resistance and high temperature resistance is useful for cutting tool applications and components in machinery and engines.

Abstract: A SiAlON ceramic body made from a starting powder mixture that includes silicon nitride powder, and one or more powders that provide aluminum, oxygen, nitrogen and ytterbium to the SiAlON ceramic. The SiAlON ceramic body includes a two phase composite comprising alpha prime SiAlON phase, which is present in an amount greater than or equal to about 20 weight percent of the two phase composite, and a beta prime SiAlON phase wherein the alpha prime SiAlON phase containing ytterbium therein. The starting silicon nitride powder contains less than or equal to about 1.6 weight percent beta-silicon nitride. The ceramic body further includes an intergranular phase that includes an intergranular crystalline phase comprising at least one of YbAG and J-phase. The overall composition of the ceramic body is YbaSibAlcOdNe, wherein when a is less than 0.05, the relative intensity of the peak associated with either one or both intergranular crystalline phases of YbAG and J-phase is greater than about 2.

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: This invention is about SiALON ceramics comprising an alpha SiAlON, a beta SiAlON and an intergranular amorphous and/or crystalline phase. Said alpha SiALON phase was prepared from a multi-cationic mixture including the element of calcium, at least one of yttrium and/or a rare earth element with atomic number greater than 62 and at least one of a rare earth element with atomic number equal or smaller than 62. The second phase beta SiALON contains elements of Si, AL, O, N. The third phase, amorphous and/or crystalline intergranular phase contains in addition to elements of Si, AL, O, N, element of calcium, at least one of yttrium and/or a rare earth element with atomic number greater than 62 and at least one of a rare earth element with atomic number equal or smaller than 62. This material with its toughness, high fracture resistance an high temperature resistance is useful for cutting tool applications and components in machinery and engines.

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: A SiAlON ceramic body made from a starting powder mixture that includes silicon nitride powder, and one or more powders that provide aluminum, oxygen, nitrogen and ytterbium to the SiAlON ceramic. The SiAlON ceramic body includes a two phase composite comprising alpha prime SiAlON phase, which is present in an amount greater than or equal to about 20 weight percent of the two phase composite, and a beta prime SiAlON phase wherein the alpha prime SiAlON phase containing ytterbium therein. The starting silicon nitride powder contains less than or equal to about 1.6 weight percent beta-silicon nitride. The ceramic body further includes an intergranular phase that includes an intergranular crystalline phase comprising at least one of YbAG and J-phase. The overall composition of the ceramic body is YbaSibAlcOdNe, wherein when a is less than 0.05, The relative intensity of the peak associated with either one or both intergranular crystalline phases of YbAG and J-phase is greater than about 2.

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: Metal oxides particularly useful for the manufacture of catalytic membranes for gas-phase oxygen separation processes having the formula: AxA′x′A″2-(x+x′)ByFey′B″2-(y+y′)O5+z where: x and x′ are greater than 0; y and y′ are greater than 0; x+x′ is equal to 2; y+y′ is less than or equal to 2; z is a number that makes the metal oxide charge neutral; A is an element selected from the lanthanide elements; A′ is an element selected from Be, Mg, Ca, Sr, Ba and Ra; A″ is an element selected from the f block lanthanides, Be, Mg, Ca, Sr, Ba and Ra; B is an element selected from the group consisting of Al, Ga, In or mixtures thereof and B″ is Co or Mg, with the exception that when B″ is Mg, A′ and A″ are not Mg. The metal oxides are useful for preparation of dense membranes which may be formed from dense thin films of the mixed metal oxide on a porous metal oxide element.

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: This invention discloses a SiAlON-based ceramic particularly suited for use as a cutting tool in the high speed chip forming machining of metals. The ceramic is composed of a SiAlON matrix including a) a phase of alpha′ SiAlON represented by the general formula of Mx(Si,Al)12(O,N)16, wherein 0<x<2 and M is at least two cationic elements, a first cationic element being Mg and optionally one or more of Ca, Sr, and Ba, and a second cationic element being one or more of Y, Sc, La and the rare earth (RE) elements; b) a phase consisting of beta' SiAlON represented by the general formula Si6−zAlzOzN8−z wherein 0<z<4.2; and c) a component containing glass, and at least one additional intergranular crystal phase that is detectable using X-ray diffraction techniques, wherein the amount of the first cationic element is 0.2 to 4 weight percent, calculated as the element, based on the SiAlON matrix, and the amount of the second cationic element of between 0.

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.