Abstract: A powdered admixture of a boron, carbon, nitrogen or silicon derivative of a first metal is combined with a source of a second metal and, optionally, a source of a third metal or an iron-group metal, subjected to densification conditions (heat and pressure), partially reacted and converted to a hard, wear resistant material. The wear resistant material contains an amount of the first metal derivative as well as a material of varying stoichiometry which is the partial reaction product of components of the powdered admixture. The material may also contain residual, unreacted portions of components other than the first metal derivative. Articles formed from this material can be useful as, for example, nozzles in abrasive or nonabrasive waterjet cutting machines and various parts of wire drawing apparatus.

Abstract: A powdered admixture of a boron, carbon, nitrogen or silicon derivative of a first metal is combined with a source of a second metal and, optionally, a source of a third metal or an iron-group metal, subjected to densification conditions (heat and pressure), partially reacted and converted to a hard, wear resistant material. The wear resistant material contains an amount of the first metal derivative as well as a material of varying stoichiometry which is the partial reaction product of components of the powdered admixture The material may also contain residual, unreacted portions of components other than the first metal derivative. Articles formed from this material can be useful as, for example, nozzles in abrasive or nonabrasive waterjet cutting machines and various parts of wire drawing apparatus.

Abstract: A method and apparatus are provided for producing a product comprising a nitride compound, such as for example silicon nitride. A reactor is provided which has a chamber defined therein which is divided into a combustion zone and a reaction zone. A combustible mixture is injected into the combustion zone in a direction generally toward the reaction zone, and is accordingly combusted in the combustion zone. At least one reactant is injected at the boundary between the zones into the reactor chamber in a direction generally parallel to the longitudinal axis of the chamber so as to react to from raw product comprising the nitride compound. According to another aspect, a raw product powder as produced by the reactor comprises silicon nitride as the nitride compound and further comprises elemental silicon.

Abstract: A process is provided for the preparation of metals, metal carbides, nitrides, borides, silicides, sulfides and phosphides by low temperature pyrolysis of a selected organometallic precursor. The precursor, in addition to containing organic ligands, contains the metal M, which is a transition metal or tin, and the element X (C, N, B, Si, S, or P), which may be bound directly to M, contained within the ligands, or both. The process enables one to provide surface coatings or shaped articles of metals, metal carbides, nitrides, and the like.

Abstract: A low temperature process is described for forming a coating or powder comprising one or more metals or metal compounds by first reacting one or more metal reactants with a halide-containing reactant to form one or more reactive intermediates capable of reacting, disproportionating, or decomposing to form a coating or powder comprising the one or more metal reactants. When one or more metal compounds are formed, either as powders or as coatings, a third reactant may be injected into a second reaction zone in the reactor to contact the one or more reactive intermediates formed in the first reaction zone to thereby form one or more metal compounds such as metal nitrides, carbides, oxides, borides, or mixtures of same.

Abstract: The invention relates to a method for producing fine grained, sintering active nitride and/or carbonitride powder of titanium as well as, optionally, of other metals of the IVA, VA and VIA group of the periodic table of elements. In order to achieve, without any considerable comminution, a grain of high purity with a low grain size, the following steps are performed:The introduction into the reactor of a reaction mixture consisting of oxides of titanium and, optionally, of other metals of the IVA, VA and VIA group of the periodic system and a carbonaceous material;providing a nitrogen atmosphere in the reactor at a decreased pressure;heating the content of the reactor to a temperature of between 800.degree. C. and 2000.degree. C., preferably between 1000.degree. C. and 1900.degree. C., and keeping the temperature within a range of between 1400.degree. C. and 1800.degree. C.

Abstract: A process for depositing a thin film of a transition metal nitride, e.g., titanium nitride, on a substrate is provided. The vapors of a transition metal organometallic coompound or a transition metal amido compound are mixed with ammonia gas and allowed to react near a substrate heated to a temperature in the range of 100.degree. C. to 400.degree. C., resulting in deposition of a film on the substrate.

Abstract: Production of composite ceramic articles by infiltration of a particulate, permeable bed or permeable preform with a polycrystalline matrix produced as a metal-oxidant reaction product, wherein the bed or preform is comprised of dross.

Abstract: A process for making titanium and chromium nitrides of known morphology by reacting potassium titanate and chromium oxide in the gas phase with NH.sub.3. The products exhibit the same morphology as the starting material.

Abstract: A process of producing nitrides of aluminum and titanium. The process involves producing a uniform dispersion of microfine particles of the corresponding metal oxide in an infusible polymer, carbonizing the resulting dispersion in a non-oxidizing atmosphere and heating the carbonized product in a nitrogen atmosphere at high temperature to cause the oxide to react with the carbon and nitrogen to form the nitride. Before carbonization, however, the dispersion is formed into shapes in which none of the oxide particles is more than about 2.5 mm (0.098 inch) from an external surface and the shapes are loosely packed in a reactor. The process can achieve a good conversion of the oxide to the nitride to yield a product of high purity and small particle size.

Abstract: A process for producing a refractory material having the form TB.sub.o, e.g. zirconium nitride (ZrN), includes a first step of mixing a first salt having the form TX.sub.n, e.g. zirconium tetrachloride (ZrCl.sub.4) and a second salt having the form A.sub.m B, e.g. lithium nitride (Li.sub.3 N) in a ratio of n/m in a container. The process also includes a second step of igniting the mixture of the first and second salts, e.g. ZrCl.sub.4 and Li.sub.3 N, whereby the refractory material, e.g. ZrN, is produced along with byproducts having forms nAX and (n/m-o)B, e.g. 4LiCl and (1/6)N.sub.2, respectively. The process further includes a third step of separating the refractory material from the byproducts by solvent extraction. The stoichiometric ratio of the second salt to the first salt is n/m, e.g. 4/3. T is selected from the group consisting of transition metals, e.g. zirconium, and tetrelides, i.e. carbon, silicon, germanium, tin and lead.

Abstract: A titanium tetrahalide is reacted with at least one disilazane to prepare a titanium-containing organometallic precursor, which is thereafter pyrolyzed to form crystalline titanium nitride.

Abstract: A thin film formation method includes the steps of holding a substrate in a reduced-pressure vapor phase reaction chamber having means for irradiating light in visible and ultraviolet ranges, supplying an organo-titanium compound containing a tri-azo group, and vapor-depositing a titanium nitride film on a surface of the substrate by an excitation reaction caused by light.

Abstract: A method for the production of a nitride of zirconium, hafnium, silicon, germanium, tin, lead, boron, aluminium, gallium, indium or thallium either alone or as mixtures is claimed. Ammonia and a halide of at least one of these elements are heated by means of a direct electric current plasma in a non-oxidizing gas in a reactor in which recirculation is induced such that the defined recirculation ratio is greater than 2.5 and preferably greater than 4.0. Any titanium halide present shall be less then 40% by weight of mixed halides.

Abstract: A method which comprises the manufacture of black titanium nitride which comprises heating ammonia and titanium halide by means of an electric plasma formed in a stream of non-oxidizing gas generated by the discharge of direct current electricty between a pair of electrodes. The heated gases are introduced through an inlet nozzle into a reactor so constructed and operated as to induce circulation of the gases with a specifically defined recirculation ratio.

Abstract: The invention relates to ceramic composite articles formed by infiltration of a particulate, permeable bed or permeable preform with a polycrystalline matrix a metal-oxidant reaction product. The bed or preform includes a dross material.

Abstract: Metal nitride powder is prepared by heating a mixture substantially containing powder of a metal oxide or a metal hydroxide in a mixed gas of ammonia gas (NH.sub.3) and a hydrocarbon gas (CmHn) at a temperature ranging from 1300.degree. C. to 1,600.degree. C., in which the mixed gas has a ratio of ammonia gas (NH.sub.3) to hydrocarbon gas (CmHn) translated into CH.sub.4, ranging from 10 (NH.sub.3) to 1.0 (CH.sub.4) to 2,000 (NH.sub.3) to 1 (CH.sub.4), by volume.The metal nitride powder contains lesser amounts of oxygen and carbon.

Abstract: A process for producing a ceramic material which is electrically conductive by reacting titanium dioxide with intercalated graphite under conditions which effect the reduction of the titanium dioxide, said product comprising an electrically conductive, corrosion-resistant, substoichiometric titanium dioxide combined chemically with an intercalant or residue thereof, for example, a metal such as copper or nickel, and the use thereof in thermal, electrical and electro-chemical applications.

Abstract: Nitride powders of high surface area, uniform small particle size and high purity are prepared by forming in an aqueous medium a homogeneous combination of a soluble or colloidally dispersible compound of a multivalent metal with a water soluble oxygen oxygenated carbonaceous polymer, e.g., by mixing an aluminum or other metal salt with polyacrylic acid or mixing colloidal hydrated alumina, or other such metal oxide, with a water soluble oxygenated carbonaceous polymer such as sucrose or methyl cellulose. The resulting precipitate or gel is dried and calcined in a nitriding atmosphere, forming a nitride powder which is highly suitable for fabrication of ceramic bodies by sintering at lower than conventional temperatures.

Abstract: The present invention relates to a process for the production of fine powder materials and the products of that process. The process involves the in-situ precipitation of second phase particles, such as ceramic or intermetalics, within a metal matrix, followed by separation of the particles from the matrix to yield a powder comprising the second phase particles. Particles formed by this process are typically in the size range of 0.01 to 10 microns and have controlled morphology, narrow size distribution, well defined stoichiometery and relatively high purity. Exemplary of second phase particles formed by this process are metal borides, carbides, nitrides, oxides, silicides and beryllides, including TiB.sub.2, ZrB.sub.2, VB.sub.2, MoB.sub.2, TiC, WC, VC, TiN, ZrSi.sub.2, MoSi.sub.2, Ti.sub.5 Si.sub.3, and TiBe.sub.12.

Abstract: The present invention is directed to polycrystalline titanium nitride and zirconium nitride coating compositions and coated articles with a I(111)/I(200) x-ray diffraction intensity ratio of at least about 75 for the titanium nitride composition and at least about 15 for the zirconium nitride composition and to a method of forming a highly oriented polycrystalline titanium nitride or zirconium nitride coating composition with a high I(111)/I(200) x-ray diffraction intensity ratio. This invention also concerns polycrystalline titanium nitride and zirconium nitride coating compositions and coated articles of the type described with an interplanar spacing, d.sub.111, of 2.460 Angstroms or less for TiN and an interplanar spacing, d.sub.111, of 2.660 Angstroms or less for ZrN and to methods for producing same. The composition is deposited upon a substrate in an evacuated chamber from a titanium or zirconium cathode source surrounded by an elongated member which overhangs the cathode to form a cathode chamber.

Abstract: The invention relates to method for producing composite ceramic articles by infiltration of a particulate, permeable bed or permeable preform with a polycrystalline matrix a metal-oxidant reaction product, and the bed or preform includes a dross material.

Abstract: A process for the manufacture of single crystal titanium nitride whiskers having uniform diameters and lengths suitable for use in the reinforcing of many matrix materials. The process is carried out by rapidly heating a mixture of titanium dioxide, fibrous carbon and a catalyst selected from individual combinations of cobalt, nickel, magnesium and calcium, for example. This mixture of solids is maintained in a closed container and is rapidly heated to a temperature of about 1300.+-.100 degrees C. for about 1 hour. During this heating a halogen, preferably a chlorine-containing gas, in conjunction with nitrogen is passed into the container whereby the titanium dioxide is converted to titanium nitride in the form of single crystal whiskers. These whiskers have a uniform diameter of about 0.5 to about 1 micron and average lengths of about 30-60 microns. The exterior surface is particularly amenable to bonding to the matrix material to which these whiskers are added for strength.

Abstract: A process for making metal nitrides, particularly titanium nitride whiskers, using a cyanide salt as a reducing agent for a metal compound in the presence of an alkali metal oxide. Sodium cyanide, various titanates and titanium oxide mixed with sodium oxide react to provide titanium nitride whiskers that can be used as reinforcement to ceramic composites.

Abstract: Methods and compostions produced thereby are provided concerning the preparation and use of high specific surface area carbides and nitrides. The carbides and nitrides can be obtained by thermal reduction of oxides in the presence of a source of carbon and nitrogen respectively, with relatively slow progressive temperature increases prior to completion of the reaction, followed by quenching. Novel metastable carbides can be obtained by carburization of nitrides having high surface area, which nitrides can be prepared by the above-described process.

Abstract: A method of making self-supporting ceramic composite structures having filler embedded therein includes infiltrating a permeable mass of filler with polycrystalline material comprising an oxidation reaction product obtained by oxidation of a parent metal such as aluminum and optionally containing therein non-oxidized constituents of the parent metal. The structure is formed by placing a parent metal adjacent to a permeable filler and heating the assembly to melt the parent metal and provide a molten body of parent metal which is contacted with a suitable vapor-phase oxidant. Within a certain temperature region and optionally aided by one or more dopants in or on the parent metal, molten parent metal will migrate through previously formed oxidation reaction product into contact with the oxidant, causing the oxidation reaction product to grow so as to embed the adjacent filler and provide the composite structure.

Abstract: A method of making metal carbide, nitride, or boride powders and mixtures thereof by direct reduction of metal compounds comprises (a) forming a reactant mixture, (b) heating the reactant mixture to temperatures that cause solid reactants to vaporize and above which the metal precursor compounds are reduced, (c) passing the heated reactant mixture through a converging-diverging nozzle designed to reduce the temperature of the mixture to a temperature and for a time sufficient for further product species to form and for nuclei to form and grow by condensation to form the product powders, and (d) exhausting the mixture and product powders from the nozzle into an expansion chamber.

Abstract: Metal carbide and metal nitride powders produced by the carbothermal reduction of one or more metal oxides reacted with a binder material and a carbonaceous additive or optionally, a binder capable of supplying carbon to the reaction. The metal oxides are selected from among SiO.sub.2, Al.sub.2 O.sub.3, TiO.sub.2, ZrO.sub.2, HfO.sub.2 and B.sub.2 O.sub.3 and are combined with the binder in the presence of carbon to form granules having a controlled pore volume. The granules are then subjected to a carbothermal reduction reaction, in the presence of a nitrogen or a neutral atmosphere, to produce metal nitrides or metal carbides respectively, having an excess of carbon incorporated therein. The product is subsequently heated to react the excess carbon within the compound with oxygen from the atmosphere to form carbon monoxide gas, which may be removed by an optional exhaust system.

Abstract: The present invention provides a sputter target for the deposition of titanium nitride films. The sputter target has a target face comprising titanium nitride having a density of at least 90% of the theoretical density of 100% pure titanium nitride. The sputter target is prepared by subjecting titanium nitride powder to hot isostatic pressure.

Abstract: A process for producing substantially oxygen-free titanium carbide, nitride or carbonitride in powder form comprises treating a gas phase reaction mixture of titanium halide, desirably TiCl.sub.4, a reductant vapor, desirably sodium or magnesium, and a reactive gas capable of furnishing carbon, nitrogen or mixtures thereof at the reaction temperature, desirably nitrogen, methane or ammonia, to a temperature in the range from 500.degree. to 1250.degree. C., preferably 800.degree. to 1100.degree. C., whereby the titanium halide is substantially simultaneously reduced and carbided, nitrided or carbonitrided. The process may also be practiced using volatile metal halides of metals such as zironium, hafnium, vanadium, niobium, tantalum and silicon for forming substantially oxygen-free carbides, nitrides or carbonitrides thereof in powder form.

Abstract: A process for making fine, uniform metal nitride powders that can be hot pressed or sintered. A metal salt is placed in a solvent with Melamine and warmed until a metal-Melamine compound forms. The solution is cooled and the metal-Melamine precipitate is calcined at a temperature below 700.degree. C. to form the metal nitrides and to avoid formation of the metal oxide.

Abstract: Metal carbide and metal nitride powders produced by the carbothermal reduction of one or more metal oxides reacted with a binder material and a carbonaceous additive or optionally, a binder capable of supplying carbon to the reaction. The metal oxides are selected from among SiO.sub.2, Al.sub.2 O.sub.3, TiO.sub.2, ZrO.sub.2, HfO.sub.2 and B.sub.2 O.sub.3 and are combined with the binder in the presence of carbon to form granules having a controlled pore volume. The granules are then subjected to a carbothermal reduction reaction, in the presence of a nitrogen or a neutral atmosphere, to produce metal nitrides or metal carbides respectively, having an excess of carbon incorporated therein. The product is subsequently heated to react the excess carbon within the compound with oxygen from the atmosphere to form carbon monoxide gas, which may be removed by an optional exhaust system.

Abstract: A chemical vapor deposition process for producing single crystal whiskers of metal carbides, nitrides, or carbonitrides involving flushing a reaction chamber including a suitable substrate surface heated to 1025.degree.-1125.degree. C., and flowing reactant gases past the substrate to form whiskers. The reactants comprise a halide of Ti, Zr, Hf, Nb, Ta or W and one or more of nitrogen, ammonia and suitable aliphatic hydrocarbons. The atomic ratio of carbon and/or nitrogen to metal is about 5:1 to 16:1; the volume ratio of hydrocarbon and/or nitrogen and/or ammonia to hydrogen is about 1:50-1:20. The preferred substrate materials are nickel or a high nickel alloy coated with TiC or TiN, or, for carbide whiskers, nickel impregnated graphite. The reactor walls and internal fixtures preferably provide the substrate surfaces. A more efficient batch process and a continuous process for whisker growth are disclosed.

Abstract: A process for making ammonolytic precursors to nitride and carbonitride ceramics. Extreme reaction conditions are not required and the precursor is a powder-like substance that produces ceramics of improved purity and morphology upon pyrolysis.

Abstract: A process for producing acidic boratozirconium chloride sols which comprises: reacting a zirconium compound with a boron compound in molar ratios of B/Zr of 0.3-1.2 together with a compound of a metal M other than boron, the metal M being selected from the group consisting of divalent, trivalent, tetravalent and pentavalent metals in molar ratios of M/Zr of about 0.01-1 in water in the presence of chloride ions in molar ratios of Cl/Zr of not less than about 1.The acidic boratozirconium chloride sol may be converted to basic boratozirconium sols by reacting the acidic sol with a basic carbonate compound such as ammonium carbonate.The sols, either acidic or basic, are readily gelled by contact with a dehydration solvent such as methanol or acetone.The gel is calcined at relatively low temperatures to provide zirconia which is either very pure or stabilized in varied degrees.

Abstract: Nitrides and carbides are prepared by intercalating a monomer, a starting material of condensate, or a prepolymer into the interlamellar spaces or the vacant spaces of the crystalline structure of a natural mineral or an inorganic compound to prepare an intercalated compound and baking the intercalated polymer compound at a temperature in the range of 1100.degree.-1700.degree. C. under a nitrogen or reducing atmosphere. The present invention provides a method for readily preparing nitrides and carbides having the increased crystallinity at a low calcination temperature. Whiskers with larger diameters of 2 to 5 .mu.m can be prepared by adding carbon powder to the intercalated compound complex.

Abstract: A method for making ultra-fine ceramic particles, in which metal powder constituting a portion of the ultra-fine ceramic particles intended for production is injected at a rate of not less than 70 grams per minute into a plasma jet so that the metal powder is vaporized. The vaporized metal powder is then mixed with a reactive gas, which includes an element consituting the other portion of the ultra-fine ceramic particles, filled in the surrounding area of the plasma jet, and thereby the vaporized metal powder and the reactive gas produce a synthetic reaction. The ultra-fine ceramic particles are produced continuously because of the reaction flame.

Abstract: Refractory metal borides, carbides, nitrides and mixtures thereof of the Group IVb, Vb and VIb metals are produced from a glass or microcrystalline gel formed from organo-metallic precursors. Typically TiO.sub.2.B.sub.2 O.sub.3 glass is produced by hydrolysis of titanium butoxide and trimethyl borate, followed by gelling/drying. The glass may have carbon inclusions or may be mixed with carbon or aluminum powder or a mixture thereof, and reacted. In the case of aluminothermic and carboaluminothermic reduction, there is a residual aluminum-containing phase in the product. Composites can also be produced by including inert materials in the reaction mixture.

Abstract: Precursors, particularly of non-oxide ceramics, are prepared by special seeding, under carefully controlled conditions. Such procedures can lead to the preparation of unique powders, which may be useful, for example as abrasives, or further processed in special manner to prepare a variety of metal substances. Such procedures can permit final firing to sintered product.

Abstract: Non-oxide powders such as carbides, nitrides, carbides/nitrides and borides are obtained by reducing an oxide powder in a reducing atmosphere, and after or concurrently with the reduction, treating the reduced powder in a carbonizing atmosphere, a nitrogenizing atmosphere, a carbonizing and nitrogenizing atmosphere, or a boronizing atmosphere. As the above oxide powder, there is used a brittle material obtained by rapid cooling of a melted oxide. The non-oxide powders obtained are utilized as a hard component of cemented carbides and cermet. These powders are fine particles having a particle size of 1.0 .mu.m or smaller and a high purity.

Abstract: The carbonitrides of metals such as those of Groups IV, V and VI of the Periodic Table are prepared by calcining a precursor obtained by (i) reacting the reaction product of ammonia and the halide of a metal with carbohydrate and/or polyvinyl alcohol, or (ii) reacting the reaction product of carbohydrate and/or polyvinyl alcohol and the halide of a metal with ammonia. The desired metallic carbonitride in the form of finely divided powder having a uniform size and excellent sintering properties can be obtained at low energy consumption.

Abstract: The carbonitrides of metals of Groups IV, V and VI of the Periodic Table are prepared by calcining a precursor obtained by (i) reacting the reaction product of ammonia and the halide of a metal selected from the group consisting of Groups IV, V and VI of the Periodic Table of Elements with polyphenol, or (ii) reacting the reaction product of polyphenol and the halide of a metal selected from the group consisting of Groups IV, V and VI of the Periodic Table of Elements with ammonia, the amount of the polyphenol being within the range defined by the following relationship: ##EQU1## wherein a is the number of hydroxyl groups contained in one molecule of the polyphenol, b is the number of moles of the polyphenol and c is the number of moles of the metallic halide. The desired metallic carbonitride in the form of finely divided powder having a uniform size and excellent sintering properties can be obtained at low energy consumption.

Abstract: Fine metallic nitride powders having a high purity are prepared, without causing any plugging or other problems in the reaction apparatus and with easy heat control of the reaction, by reacting a metallic halide with liquid ammonia in the presence of an organic solvent which has a specific gravity higher than that of liquid ammonia, and also is not miscible or is only slightly miscible with liquid ammonia at a reaction temperature. The process according to the present invention is effected by introducing the metallic halide into the lower organic solvent layer of the reaction system.

Abstract: Finely divided borides, carbides, and nitrides of metals of Groups III-VI of the Periodic Table, formed by reacting vaporous metal halide and a boron, carbon, or nitrogen source reactant at high temperatures, e.g., 1500.degree. C., are separated from gaseous reactor effluent stream at temperatures between about 200.degree. C. and 1500.degree. C. with the use of a porous sintered filter. By separating the finely divided product from the effluent stream before the stream cools to below about 200.degree. C., adsorption of impurities, e.g., unreacted metal halide or metal subhalides, on the product is reduced. The use of a filter, e.g., a porous sintered filter, avoids the size classification of product which may result when cyclones and a bag filter are used to collect product.

Abstract: A method is provided for producing a selected metal nitride utilizing a salt bath. The selected metal is introduced into the salt bath in the presence of gaseous nitrogen and at least a certain amount of a halide of the selected metal. The salt bath is maintained at a temperature above its melting point for time sufficient to form a precipitate of the desired amount of a nitride of the selected metal. In accordance with a preferred embodment, the pressure is thereafter reduced to less than atmospheric and the temperature increased above the boiling point of the salt for a time sufficient to volatilize the molten salt which is removed to leave a precipitate of the selected metal nitride. The method is particularly applicable to the production of the mononitrides of uranium, plutonium, thorium, and mixtures thereof.

Abstract: Helical flow of hot plasma gas, e.g., hydrogen gas, produced by a gas vortex stabilized plasma arc is cancelled by introducing attenuating gas, e.g., hydrogen gas, into the hot plasma gas in a manner such that the attenuating gas assumes a vortical direction opposite to the helical flow of the hot plasma gas. The resulting gas stream is well-collimated. The well-collimated plasma gas stream is used in the preparation of finely-divided refractory metal and metalloid carbides, borides, nitrides, silicides and sulfides. Reactants for the preparation of the aforementioned refractory powders are introduced into the collimated plasma gas stream. The reaction is conducted in the gas phase within a reactor and solid, finely-divided refractory powder removed from the reactor.

Abstract: The preparation of metal and metalloid carbides, borides, nitrides silicides and sulfides by reaction in the vapor phase of the corresponding vaporous metal halide, e.g., metal chloride, with a source of carbon, boron, nitrogen, silicon or sulfur respectively in a reactor is described. Reactants can be introduced into the reactor through a reactant inlet nozzle assembly. Inhibition and often substantial elimination of product growth on exposed surfaces of such assembly is accomplished by introducing the corresponding substantially anhydrous hydrogen halide, e.g., hydrogen chloride, into the principal reactant mixing zone.

Abstract: A method of producing an aluminum oxide and tungstate powder for insulating cathode heaters includes mixing a finely divided aluminum oxide powder with ammonium tungstate, rinsing out excess ammonium tungstate, drying the mixture and heating in a nitrogen-hydrogen atmosphere to about 700.degree.C.

Abstract: Fine metallic nitride powders having a high purity are prepared, without causing any plugging or other problems in the reaction apparatus and with easy heat control of the reaction, by reacting a metallic halide with liquid ammonia in the presence of an organic solvent which has a specific gravity higher than that of liquid ammonia, and also is not miscible or is only slightly miscible with liquid ammonia at a reaction temperature. The process according to the present invention is effected by introducing the metallic halide into the lower organic solvent layer of the reaction system.

Abstract: A process for making titanium nitride powder by reaction of titanium phosphates with sodium cyanide.