Abstract: The invention relates to an aluminofluorosilicate glass for use in a material for dental restoration, which has the following features:a) a ratio of Al (calculated as Al.sub.2 O.sub.3) to Si (calculated as SiO.sub.2) of 0.57-1.12 by mass;b) a total content of Mg (calculated as MgO) and Ba (calculated as BaO) of 29-36% by mass;c) a ratio of Mg (calculated as MgO) to Ba (calculated as BaO) of 0.028-0.32 by mass;d) a content of P (calculated as P.sub.2 O.sub.5) of 2-10% by mass.The glass according to the invention has a high radiopacity, and the refractive index n.sub.D for visible light can be adjusted by varying the phosphorus content.

Abstract: A novel method for joining aluminum nitride-series substrates to each other is provided in the substantial absence of an intervening third layer at the joining interface between the substrates. In the method, the aluminum nitride-series substrates are joined to each other by interposing a joining agent between the substrates, heating the substrates and the joining agent to a first temperature range of at least the melting point of the joining agent to melt the joining agent and liquefy particles of the aluminum nitride at the neighborhood of the interfaces between the melted joining agent and the substrates, and then heating the joining agent and the substrates to a temperature range higher than the temperature range of the first process but lower than the melting point of the substrates to exhaust the joining agent from between the substrates.

Abstract: Hydrofluoric acid-resistant ceramic mortar compositions containing a hydrofluoric acid-resistant grog having a particle size distribution imparting a high particle packing fraction to the mortar composition and a binding phase containing a metal salt having a particle size distribution imparting plasticity to the mortar composition selected from hydrofluoric acid-insoluble fluoride salts, metal salts capable of forming hydrofluoric acid-insoluble fluoride salts upon reaction with a fluorinating reagent and mixtures thereof. Methods for forming hydrofluoric acid-resistant ceramic mortar compositions from non-fluoride metal salts are also disclosed as well as methods for bonding refractory bricks into a brickwork unit with the ceramic mortars of the invention. Brickwork units prepared using the ceramic mortar compositions of the invention by the methods of the invention are also described.

Abstract: There is provided a belt coating material for a belt type continuous casting, which is capable of adsorbing the intermediate between a cast slab and the coating material to prevent the intermediate from remaining on the slab, and reducing the averaged heat flux during the casting to avoid an occurrence of cracking in a medium carbon steel. The belt coating material comprises: (1) a powder having a composition comprising 10 to 40 weight % of SiO.sub.2, 1 to 10 weight % of Al.sub.2 O.sub.3, 10 to 40 weight % of CaO, 10 to 30 weight % of Na.sub.2 O, 1 to 10 weight % of MgO, 10 to 20 weight % of F, and 1 to 5 weight % of LiO.sub.2, the powder being prepared by once melting the blended components, solidifying the melt, and crushing it into the powder to adjust the average grain diameter of the powder to be equal to or smaller than 10 .mu.m; (2) 0.1 to 10 weight % of graphite mixed into the powder to provide a mixture, the graphite having the same grain diameter with the powder; and (3) 0.

Abstract: There is provided a fluoride-ion sustained release pre-formed glass ionomer filler comprising a powdery reaction product of polyalkenoic acid with a fluorine-containing glass, and a method of producing the same. There is also provided a dental composition containing the filler. The fluoride-ion sustained release pre-formed glass ionomer filler is long capable of releasing fluoride ions in the presence of water without involving disintegration. The dental composition of the invention is useful particularly for prevention of dental caries and like trouble.

Abstract: A composition useful as a restorative material includes a curable matrix with whiskers which preferably have a silicon dioxide containing coating thereon that are then silanized and may also include optional particulate filler of the type which may release fluorides. The polymeric matrix bonds more tightly to the whiskers due to the coating of silicon dioxide on the surface of the whiskers and the coaction between said silicon dioxide and the silane compound. Particles adhered to the whisker also enhance the mechanical properties by virtue of the whisker's surface being thereby roughened. A method of manufacture is also disclosed.

Abstract: A composition for growing a laser crystal is represented by the formula of Li ?R.sub.n .alpha..sub.1-n! ?(Ga.sub.p In.sub.q) .beta..sub.1-p-q ! F.sub.6+n where n is within a range from 10.sup.-5 to 0.1, each of p and q is within a range from 0 to 0.6, a total of p and q is within a range from 0.001 to 0.6, .alpha. is at least one member selected from the group consisting of Ca, Sr, Ba and Na, .beta. is at least one member selected from the group consisting of Al, Cr, Ni, Co and Fe, and R is a rare-earth element. The composition enables the distribution coefficient of rare-earth element to get closer to 1 and thus enables the laser crystal to have a high and uniform concentration of rare-earth element and to have a large size.

Abstract: The invention relates to pulverulent ferroelectric perovskites having piezoelectric properties up to a temperature of approximately 300.degree. C. as well as their manufacturing processes. The processes include a step wherein fluorine ions are inserted into the perovskites at anionic sites and/or oxygen vacancies. The perovskites are used as raw materials for the production of piezoelectric ceramics which find application in a variety of fields, such as electroacoustic transducers, piezoelectric motors, welding and industrial cleaning.

Abstract: A superconductive material is in composition expressed as Y.sub.0.33 Ba.sub.0.67).sub.a Cu.sub.b (OF).sub.c. The usual a, b and c are so selected as to satisfy a relation expression ax (mix valence of A)+bx (mix valence of B)=cx (mix valence of C).

Abstract: A glass frit for firing in reducing environments includes an unusually large amount of calcium fluoride melted therein. Also, a copper conductive composition includes the glass frit with an unusually large amount of calcium fluoride. This copper conductive composition may be a paste prepared for screen printing, in which case an appropriate screening agent known to one of ordinary skill may be incorporated, or the composition may be a fired film formed upon a suitable substrate. A high power surge resistor also incorporates the glass frit.

Abstract: Halide glasses having particular utility as hosts for praseodynmium in order to provide optical amplification by laser activity have a halide content provided as a small proportion, e.g., 1-10 percent, of choride with the remainder as fluoride. The metal content is similar to conventional ZBLAN glasses. The replacement of A1 by Y and In and/or the partial replacement of Na by Cs has synergistic benefits. PR.sup.3+ constitutes a good lasing species for amplifying telecommunication signals at 1300 nm using pumped radiation at 1020 nm.

Abstract: The present invention provides an infrared ray transmitting material, even large-sized one being manufacturable at a low price, consisting of a polycrystal not liable to cleavage, which makes only a slight absorption of infrared rays all over the region of 8-11 .mu.m wave lengths, thus being highly transmissive. The material is a polycrystalline barium fluoride sintered body excellent in transmission to infrared region of 8-11 .mu.m wave lengths, one that is most excellent in the infrared transmission being produced by a method comprising the hot press sintering and the HIP treatment in combination, one that gives somewhat inferior transmission but which is low-priced by a method comprising the CIP molding and the normal pressure sintering in combination, and one that regarded as intermediate between the aforementioned two by a method comprising the CIP molding, normal-pressure sintering and the HIP treatment in combination, in all cases entirely without addition of any binder or sintering aid.

Abstract: A disordered fluorite-type photochemical hole burning crystal contains Sm.sup.2+ as active ions, and a composition except Sm.sup.2+ is represented by a general formula .alpha.-(MALn)F.sub.6-v X.sub.v where 0.ltoreq.v.ltoreq.1, and M is an element selected from Ca, Sr and Ba, A is an element selected from Na, K, Rb and Cs, Ln is an element selected from Y, La, Gd and Ce, and X is an element selected from Cl, Br and I. Stable hole burning occurs at the room temperature to create narrow holes. The crystal can be used as a superior optical recording material for a room temperature operation.

Abstract: A description is given of a solid oxide-ceramic superconductor containing copper in the crystal lattice which is composed of crystals which are arranged essentially in parallel and intergrown with one another and which also contains, per 100 g of copper in the superconductor, 0.04 to 0.5 mol of CuF.sub.2 or KF, and of a sinter process for producing it. The copper-containing superconductor may be made up, for example, of bismuth, strontium, calcium or of bismuth, strontium, calcium, lead and also copper and oxygen.

Abstract: Vitreous solid compositions of formula I:Te.sub.w Se.sub.y X.sub.x Z.sub.z (I)whereinX represents at least one halogen selected from chlorine, bromine and iodine,Z represents at least one element selected from As, Sb and Bi,w, x, y and z represent the molar percentages respectively of elements Te, X, Se and Z,w being a number varying from 5 to 50,x being a number varying from 5 to x.sub.1,y being a number varying from 5 to 80,z being a number varying from 5 to z.sub.1,the numbers w, x, y and z being such that the sum (w+x+y+z) is equal to 100,the numbers x.sub.1 and z.sub.1 being such that:when X represents mostly iodine, x.sub.1 =50 and z.sub.1 =60,when X represents mostly bromine, x.sub.1 =60 and z.sub.1 =50, andwhen X represents mostly chlorine, x.sub.1 =60 and z.sub.

Abstract: This invention is directed to the production of transparent glasses exhibiting transmission far into the infrared regime of the radiation spectrum. The glasses consist essentially, in mole percent, of 42-55% CdF.sub.2 and/or CdCl.sub.2, 30-40% NaF and/or NaCl, 2-20% total of BaF.sub.2 and/or BaCl.sub.2 +KF and/or KCl, consisting of 0-15% BaF.sub.2 and/or BaCl.sub.2 and 0-7% KF and/or KCl, 1-12% total of at least one stabilizing metal halide selected from the group LiX, BeX.sub.2, MgX.sub.2, MnX.sub.2, PbX.sub.2, TlX, COX.sub.2, and ZnX.sub.2, and 0,005-0.5% REX.sub.3, wherein Re is at least one rare earth metal selected from the lanthanide series of rare earth metals and X is at least one halide selected from the group consisting of fluoride, chloride, and bromide. The preferred glasses contain at least 2% each of BaF.sub.2 and/or BaCl.sub.2 and KF and/or KCl.

Abstract: Disclosed is a process for preparing Li.sub.2 O--Al.sub.2 O.sub.3 --SiO.sub.2 ceramic sintered bodies. Lithium fluoride powder is added to a calcined Li.sub.2 O--Al.sub.2 O.sub.3 --SiO.sub.2 powder prepared by sol-gel process as sintering agent. The resulting powder mixture is compressed into a molded article and sintered at a temperature of 950.degree.-1250.degree. C. to obtain the sintered bodies of the invention. The sintered bodies according to the present invention have a relative density of 97.9% and a thermal expansion coefficient of 10.sup.-7 /.degree.C. magnitude.

Abstract: An inventive process for forming a conductive, particulate, fluorine-doped, zinc oxide product which is doped throughout. The process comprises the step of reacting vapor phase reactants in a vapor phase oxidation system and at a temperature sufficient to form the conductive, particulate, fluorine-doped, zinc oxide product. The vapor phase reactants used in the inventive process comprise: elemental zinc vapor; at least one fluorine source; and at least one water source.

Abstract: Complex superconducting oxides are fabricated through appropriate selection and use of fundamental superconducting "building blocks." In this fashion, the invention provides a rationalized method of fabricating complex oxides having desirably high T.sub.c values. In another aspect of the invention, novel, 112 and 12 superconducting oxides are described.

Abstract: This invention is directed to the production of transparent glasses exhibiting transmission far into the infrared regime of the radiation spectrum. The glasses consist essentially, in mole percent, of 42-55% CdF.sub.2 and/or CdCl.sub.2, 2-15% BaF.sub.2 and/or BaCl.sub.2, 30-40% NaF and/or NaCl, 2-7% KF and/or KCl, 1-12% total of at least one stabilizing metal halide selected from the group LiX, BeX.sub.2, MgX.sub.2, MnX.sub.2, PbX.sub.2, TlX, CoX.sub.2, and ZnX.sub.2, and 0.005-0.5% ReX.sub.3, wherein Re is at least one rare earth metal selected from the lanthanide series of rare earth metals and X is at least one halide selected from the group consisting of fluoride, chloride, and bromide.

Abstract: An oxide type superconducting material comprising a plurality of metal species and oxygen in combined form, said superconducting material improved by the addition of a parametric modifier.

Abstract: The present invention is a method for producing swellable or nonswellable fluorine mica at a relatively lower temperature by heating a powdery mixture comprising 10 to 35% by weight of an alkali silicofluoride as the main component optionally together with an alkali fluoride and the balance of talc. This fluorine mica is used for pigments, etc.

Abstract: A process for heat-treating a composite material is disclosed. The composite material contains alumina, free silicon, and a beta-sialon material of the formula Si.sub.6-z Al.sub.z O.sub.z N.sub.8-z, wherein z is from 2.5 to 3.5. In the heat treatment process, the composite material is subjected to temperatures of 800-1,000 degrees centigrade, 1,240 to 1,260 degrees centigrade, and 1,400 to 1,450 degrees centigrade for various times and under specified conditions.

Abstract: The present invention provides a magnetic disc file which comprises a thin film magnetic disc for recording information, a motor for rotating the thin film magnetic disc, a magnetic head for writing and reading information, the head being provided with a flying slider, and a carriage for supporting the magnetic head and changing the position of the head in respect of the thin film magnetic disc, the flying height of the flying slider from the thin film magnetic disc being set in the range of 0.05 to 0.15 .mu.m, and the slider being not in contact with the thin film magnetic disc during the seeking operation on the thin film magnetic disc, the slider being a sintered body containing a metal oxide or oxides in an amount of 50 vol % or more based on the total of said body and containing 0.

Abstract: The ceramic sinter is composed of a metal oxide such as ZrO.sub.2 and 10-90 vol. % of metal fluoride which is selected from the group having not less than 2.5 electronegativity difference between fluoride and the metal element.The ceramic sinter has a thermal expansion coefficient of 15-20.times.10.sup.-6 /.degree.C. and is suitable for bonding with general use metals such as stainless steel to form a composite body of the ceramic sinter and the metal without causing a substantial thermal stress at the juncture thereof.

Abstract: An oxide type superconducting material comprising a plurality of metal species and oxygen in combined form, said superconducting material improved by the addition of a parametric modifier.

Abstract: Transparent, electrically conductive and infrared-reflective films of zinc oxyfluoride are produced by chemical vapor deposition from vapor mixtures of zinc, oxygen and fluorine-containing compounds. The substitution of fluorine for some of the oxygen in zinc oxide results in dramatic increases in the electrical conductivity. For example, diethyl zinc, ethyl alcohol and hexafluoropropene vapors are reacted over a glass surface at 400.degree. C. to form a visibly transparent, electrically conductive, infrared reflective and ultraviolet absorptive film of zinc oxyfluoride. Such films are useful in liquid crystal display devices, solar cells, electrochromic absorbers and reflectors, energy-conserving heat mirrors, and antistatic coatings.

Abstract: A self-hardenable material comprising a calcium phosphate having an atomic ratio of Ca/P of 1.4 to 1.6, a difficultly water-soluble inorganic fluoride, an organic or inorganic acid and water is provided. For example, when the hardenable material is frilled in the form of slurry or paste in a necessary part in vivo or in the dental cavity, it hardens within a short time to form a stable apatite type product.

Abstract: There is disclosed a highly densified, sintered aluminum nitride body having a thermal conductivity in excess of 200 W/m.degree.K. and a strong resistance to attack by hot HC1. There is also disclosed a method of sintering aluminum nitride bodies which employs a variable thermal cycle whereby the body is either heated slowly through a pre-sintering temperature range of 1300.degree. to 1750.degree. C., or held at a temperature within that range for at least a half hour. Optionally, a green aluminum nitride body may be provided with up to 10% by weight of at least one metal fluoride dopant, and may be provided with a sufficient weight to maintain flatness during firing.

Abstract: The present invention relates to solid materials for use as solid electrolytes for a fuel cell. Specifically, the invention relates to a solid O.sup.2- conducting material for use as an electrolyte for a fuel cell, comprising:a monocrystal or polycrystal structure of the formula: A.sub.1-x B.sub.x Z, whereinA is independently selected from lanthanum, cerium, neodymium, praseodymium, scandium or mixtures thereof;B is independently selected from strontium, calcium, barium or magnesium, andx is between about 0 and 0.9999,Z is selected from the group consisting of F.sub.3-x and O.sub.c F.sub.d where F is fluorine, O is oxygen, x is between about 0 and 0.9999 and 2c+d=3-x,wherein c is between 0.0001 and 1.5 and d is between 0.0001 and less than or equal to 3, with the proviso when A is lanthanum, Z is F.sub.3-x and x is 0, the solid material is only a monocrystal.

Abstract: This invention sets forth an agent for filling bone and tooth defects, for building up bone, for bone-contact layers and for the replacement of bones and the roots of teeth, which contains calcium phosphate apatite having carbonate and alkali portions, all ions being definedly integrated in the crystal lattice; use is optionally made together with additives and/or diluents both tolerated by the body. Furthermore, it sets forth the use of this apatite for filling bone and tooth defects, for building up bone, for bone-contact layers, as a replacement for bones and the roots of teeth and as an implant article consisting completely or partially of this apatite or consisting of a material known for implant articles and being coated completely or partially with a layer of this apatite.

Abstract: A heat and water resistant paper prepared with ceramic fiber and a 90-10 to 10-90 mixture of magnesium fluorhectorite and guanidinium fluorhectorite provides improved tensile strength. The fluorhectorites are flocculated from lithium fluorhectorite by ion exchange with 1 M solution of magnesium chloride and guanidinium chloride.

Abstract: The invention concerns a method for the manufacture of oxide ceramic bodies with a high ratio of surface area to mass and high strength.These bodies manufactured by the method according to the invention are particularly suitable for forming composite materials, to increase the strength and refractoriness of components, for example and above all those of plastic and light metal components.The method according to the invention consists of the solidification of eutectic, eutectoid or peritectic oxide-halide system, wherein the halides can subsequently be removed by dissolution and re-used. According to the system of raw materials, selected composition, temperature gradient and rate of solidification, plates firmly bonded together by twinning, separate plates or columnar oxide bodies can be produced, with particularly low wall thicknesses or diameters of, for example, approximately 0.1 to 0.2 .mu.m.

Abstract: A dielectric ceramic having the composition represented by the general formula (I):Ba.sub.x A.sub.y B.sub.1-x-y F.sub.z O.sub.wwherein A is at least one selected from the group consisting of Mg, Zn, Ni and Co; B is at least one selected from Ta and Nb; x, y, and z are numbers represented by 0.48.ltoreq.x.ltoreq.0.52, 0.15.ltoreq.y.ltoreq.0.19 and 0.00025.ltoreq.z.ltoreq.0.05, respectively; and w is a number such that the total electric charges of cations of A and B and anions of F are neutralized to make the ceramic substantially neutral as a whole, and a process of preparing the dielectric ceramic. This ceramic has a high dielectric constant and unloaded Q and has a small temperature coefficient of resonance frequency.

Abstract: A complex oxide comprising zirconium oxide and an oxide of at least one metal selected from the group consisting of an alkali metals, alkaline earth metals, silicon and lead is mixed with pottery stone, magnesium fluoride, a compound capable of forming magnesium oxide, a compound capable of forming potassium oxide and a compound capable of forming boron oxide to obtain a composition in which the contents of elements in 100 parts by weight of the total amount exclusive of the ignition loss are 16 to 25 parts of silicon, 6 to 9 parts of aluminum, 5.5 to 12 parts of potassium, 4.7 to 15 parts of magnesium, 0.7 to 5.0 parts of zirconium, 0.7 to 3.2 parts of boron, 3.0 to 9.3 parts of fluorine, up to 7.0 parts of metals other than the foregoing elements, and the balance being oxygen. This composition is heat-melted and then cooled from a temperature higher at least 50.degree. C. than the glass transition temperature of a vitreous body to be formed to a temperature lower by at least 70.degree. C.

Abstract: Sheets and laminated composites are described which are prepared with epoxy and flocculated vermiculite and mica dispersions. Processes and procedures are also described to obtain film and sheet materials from the flocculated silicate and epoxy dispersions.

Abstract: A colored frit prepared by fusing by heating a material composition comprising a devitrifying substance, a coloring agent and glass, and a method for manufacturing an artificial stone made by utilizing the colored frit. In the method of manufacturing artificial stones, the colored frits alone or a mixture of at least one kind of the colored frits and at least one kind of the colored frits and at least one kind of frits containing fluormicas are sintered, so that the colored frits are devitrified and the colors of the devitrified colored frits become distinctly visible to a viewer. This produces artificial stones having a wide variety of distinct colors and patterns.

Abstract: An aluminum nitride ceramic body with a thermal conductivity of at least 0.5 W/cm.multidot.K at 25.degree. C. is produced by shaping a particulate mixture of aluminum nitride powder and an additive selected from the group consisting of YF.sub.3, ScF.sub.3, LF.sub.3 where L is La, Ce, Pr, Nd, Sm, Gd, Dy, Ho and Er and a mixture thereof into a compact and liquid phase sintering the compact.

Abstract: A refractory composition for use in contact with molten aluminum alloys containing a refractory aggregate, a binder and an additive for imparting aluminum resistance to the refractory composition, the additive comprising synthetic calcium fluoride containing aluminum borate aggregate consisting essentially of 10 to 50% by weight boron oxide, 10-50% by weight of aluminum oxide, and 25-75% by weight calcium flouride. The synthetic aggregate may be prepared by blending boric acid, aluminum oxide, and fluorspor and firing the resultant blend at a temperature above 800.degree. C. to form a synthetic aluminum borate having calcium fluoride contained in its insoluble structure.

Abstract: Toughening agents are produced by the application of high pressure, sufficient to transform a powder material into a denser high pressure polymorph. When the pressure is released, the high pressure phase is retrieved metastably at ambient conditions of pressure and temperature. The amount of high pressure phase retained at ambient conditions depends on the relative hydrostaticity of the pressurized environment and particle size of the powder. The high pressure phase is almost completely retained in a hydrostatic environment. One embodiment of the process of the present invention produces pressure transformation toughened zirconia comprising a high pressure phase having a symmetry no greater than tetragonal (defined as tetragonal II) dispersed within a matrix of a less dense monoclinic phase.

Abstract: A cement for vessels for containing molten alloys of aluminum with metals selected from the group consisting of lithium, magnesium, zinc and copper is shown that forms a hard sintered crust for containing the molten alloy in the vessel with a backing of granular cement for controlling thermal stress while also providing a vitrifying flux means in the cement mix for effecting a sealing of any cracks that may form in the crust by reacting with any hot alloy flowing through such a crack to contain the leak as a metal spur.

Abstract: Disclosed are compositions of flocced mineral materials combined with fibers and/or binders. These compositions may be utilized to prepare high temperature resistant, water resistant articles. These materials are prepared by utilizing, as a starting material, a gellable layered swelled silicate that has an average charge per structural unit that ranges from about -0.5 to -1 and which contains interstitial cations which promote swelling with a source of at least one species of an exchange cation that is derived from guanidine or compounds closely related thereto.

Abstract: Disclosed are an aluminum nitride sintered body comprising aluminum nitride, rare earth element-aluminum compounds and alkaline earth metal-aluminum compounds, and a process for producing an aluminum nitride sintered body, which comprises adding to aluminum nitride powder:(a) powder of at least one compound selected from the group consisting of rare earth element oxides, rare earth element fluorides and compounds capable of being converted into these oxides or fluorides by calcination, and(b) powder of at least one compound selected from the group consisting of alkaline earth metal oxides, alkali earth metal fluorides and compounds capable of being converted into these oxides or fluorides by calcination, in a total amount of 0.01 to 20 wt % as calculated on the weight of the oxides or the fluorides, and then molding and sintering the resultant mixture.

Abstract: A low-temperature sinterable ceramic composition comprising 1 to 20% by weight of Al.sub.2 O.sub.3, 15 to 50% by weight of SiO.sub.2, 0 to 5% by weight of MgO, 3 to 18% by weight of CaO, 0 to 5% by weight of TiO.sub.2, 1 to 8% by weight of B.sub.2 O.sub.3, 0 to 2% by weight of Li.sub.2 O, 20 to 80% by weight of at least one of zircon, mullite and spinnel, and 1 to 12% by weight of a fluoride selected from CaF.sub.2, MgF.sub.2, LiF, AlF.sub.3, MnF.sub.2, BaF.sub.2 and SrF.sub.2.

Abstract: This invention is directed to the production of nitride-based ceramic bodies selected from the group of AlN and Si.sub.3 N.sub.4 which can be sintered to near theoretical densities at temperatures at least 200.degree. C. lower than those required for the pure materials. Such bodies are densified through the addition of a metal fluoride selected from the group of aluminum, barium, calcium, srtrontium, yttrium, the lanthanide rare earth metals, and mixtures thereof. Up to 80% by weight of said metal fluoride may be included but, generally, such additions will be held between 5-30% by weight. AlN bodies exhibiting very high thermal conductivity can be prepared by sintering with a metal fluoride selected from the group of barium, calcium, strontium, yttrium, the lanthanide rare earth metals, and mixtures thereof.

Abstract: Disclosed are flocced mineral materials which may be utilized to prepare high temperature resistant, water resistant articles. These materials are prepared by utilizing, as a starting material, a gellable layered swelled silicate that has an average charge per structural unit that ranges from about -0.5 to -1 and which contains interstitial cations which promote swelling with a source of at least one species of an exchange cation that is derived from guanidine or compounds closely related thereto.

Abstract: An aluminum nitride sintered body prepared by a process comprising adding to a principal component of aluminum nitride an additional component of at least one of fluorides of alkaline earth metals selected from the group consisting of calcium (Ca), strontium (Sr) and barium (Ba) or at least one of fluorides of rare earth elements added in an amount of 0.01 to 20% by weight, followed by sintering.

Abstract: A composite is produced by infiltrating the open pores of a polycrystalline silicon nitride body with a member selected from the group consisting of barium fluoride, calcium fluoride, magnesium fluoride, strontium fluoride, cerium fluoride, dysprosium fluoride, gadolinium fluoride, lanthanum fluoride, samarium fluoride, yttrium fluoride, and a mixture of said fluoride with a metal oxide.

Abstract: A composite is produced by infiltrating the open pores of a polycrystalline silicon nitride body with a member selected from the group consisting of barium fluoride, calcium fluoride, magnesium fluoride, strontium fluoride, cerium fluoride, dysprosium fluoride, gadolinium fluoride, lanthanum fluoride, samarium fluoride, yttrium fluoride, and a mixture of said fluoride with a metal oxide.

Abstract: A composite is produced by forming a porous compact of a ceramic member selected from the group consisting of boron carbide, hafnium carbide, hafnium nitride, niobium carbide, niobium nitride, silicon carbide, silicon nitride, tantalum carbide, tantalum nitride, titanium carbide, titanium nitride, vanadium carbide, vanadium nitride, zirconium carbide and zirconium nitride, and infiltrating the compact with a member selected from the group consisting of barium fluoride, calcium fluoride, magnesium fluoride, strontium fluoride, cerium fluoride, dysprosium fluoride, gadolinium fluoride, lanthanum fluoride, samarium fluoride, yttrium fluoride, and a mixture of said fluoride with a metal oxide.