Abstract: A manufacturing method of a molten carbonate fuel cell (MCFC) anode includes the steps of: forming a Ni coating solution for coating a surface of alumina powder by mixing nickel acetate and ethanol in a predetermined ratio, adding distilled water to the mixture in a predetermined ratio and refluxing the resultant; coating a pre-treated surface of alumina powder with the Ni coating solution; mixing a pure Ni powder and Ni-coated alumina powder obtained in the Ni coating step, and then forming a green sheet of an electrode from the mixture of pure Ni powder and Ni-coated alumina powder; and drying and sintering the electrode in a reducing atmosphere. Thus, various problems in manufacturing conventional anodes of Ni-metal alloy powder can be solved, and an anode for an MCFC having greatly enhanced creep resistance and electrode performance can be obtained.

Abstract: The invention concerns a metal powder composition for warm compaction comprising an iron-based powder and lubricant powder consisting of a polycarboxylic acid amide wax having a melting point peak in the range of 180° to 210° C.

Abstract: The invention relates to a process for the production of metallic and metal-ceramic composite components by powder injection molding of a system comprising a metal composite powder, a binder and optionally a ceramic component, where the metal composite powder used is mixed with a protecting liquid in an inert atmosphere before the mixing with the binder. The invention furthermore relates to molybdenum/copper and tungsten/copper composite powders which have a primary metal particle size of predominantly <2 &mgr;m, an oxygen content of <0.8% by weight and optionally a ceramic component, to the use of these composite powders for the production of composite components by powder injection molding, and to a process for the preparation of composite powders in which oxides of molybdenum or tungsten and of copper are mixed, dry-ground and reduced using hydrogen at a temperature of from 800 to 1050° C., and a ceramic component is optionally admixed with the resultant metal composite powder.

Abstract: Disclosed is a method for the compaction of a soft magnetic powder capable of manufacturing a green compact which has attained high density and high strength, is excellent in mechanical properties and magnetic properties, and does not cause a reduction in electrical resistance. Soft magnetic powder particles individually surface-coated with an insulating vitreous layer containing P, Mg, B, and Fe as essential components are used, and a lubricant is applied to the inner wall surface of a compaction die. The soft magnetic powder is subjected to compaction at from not less than room temperature to less than 50° C. without mixing the lubricant with the soft magnetic powder, followed by annealing at from 50 to 300° C.

Abstract: A magnetically soft, moldable composite material include powder grains coated with nonmagnetic thermoplastic compounds or with molecular precursors for ceramics or with intermetallic compounds, the magnetic properties of the magnetically soft composite material being adjustable in that fashion. Also described is a method for manufacturing a magnetically soft, shapable composite material coated in that fashion, which can subsequently be processed into shaped parts.

Abstract: A paste composition, including a binding agent charged with metallic powder, to be used in a solid freeform fabrication procedure, comprising:

Abstract: The present invention relates to a coated cemented carbide insert with a binder phase enriched surface zone. The WC-grains have an average grain size in the range 1.0-3.5 &mgr;m, preferably 1.3-3.0 &mgr;m and the number of WC-grains larger than 2 times the average grain size is less than 10 grains/cm2 measured on a representative polished section 0.5 cm2 large, preferably less than 5 grains/cm2, and the number larger than 3 times the average grain size is less than 5 grains/cm2, preferably less than 3 grains/cm2. The cemented carbide is made by powder metallurgical methods and is in particular characterized in that the cooling rate, CR, from the sintering temperature, ST, exhibits the relationship 10<CR·(ST-1300)/1000<17.

Abstract: A blade material, containing diamond particles below about 100 &mgr;m in diameter, is formed as a cutting material where the diamond particles serve as cutting agents while being fixed in a retaining matrix. The retaining matrix substantially includes Titanium or a Titanium alloy containing more than about 50 wt % of Titanium and fixes the diamond particles in place through a multi-step process.

Abstract: The invention concerns a process for the preparation of a compressed soft magnetic powder core comprising the steps of compacting an iron based powder the particles of which are insulated by a chromium containing layer, at a pressure between 300 and 1500 Mpa. The compacted body is then heated to a temperature sufficient for achieving stress relief and recrystallization of the iron base material.

Abstract: A method of treatment a metal powder to increase its surface area is presented. The metal powder to be treated is selected from a group consisting of tantalum, niobium and mixtures thereof. The method utilizes mechanical alloying applied to an initial selected metal powder and an auxiliary substance having relatively weak corrosion resistance as compared to that of the selected metal. The mechanical alloying is continued until a solid solution of the selected metal and the substance is obtained, in which the selected metal particle has a substantially developed surface area and is at least partly wetted with the substance substantially within a surface region of the selected metal particle. The substance is then removed from the obtained solid solution, thereby leaving the selected metal particles with the substantially developed surface area free of the substance.

Abstract: The invention improves the thermal conductivity of the material powder to be fired and also makes it possible to produce an amorphous magnetically soft body within a shortened period of time. The amorphous magnetically soft body is produced by preforming the material powder into a body first, and heating the preformed body without pressing. Stated more specifically, an amorphous magnetically soft body is produced from a material powder comprising a powder of an amorphous magnetically soft alloy, a glass having a softening point lower than the crystallization starting temperature of the alloy and a binding resin, by pressing the material powder in a preforming die to prepare a preformed body by the binding property of the resin, and firing the preformed body without pressing at a temperature higher than the softening point of the glass and lower than the crystallization starting temperature of the alloy to join the particles of the alloy with the glass.

Abstract: A composite material includes a metallic second phase dispersed in a metallic matrix material. The metallic second phase has a grain structure that is at least partially martensitic. The second phase material is preferably an alloy of nickel and titanium, each present in the range from 48 to 52 atomic %, optionally in combination with further additives. The second phase particles can be present in the form of granular particles, wires, fibers, whiskers, or layers, making up 5 to 60 vol. % of the overall composite material. The matrix material is preferably an aluminum alloy. The composite material has a high damping capacity and a high tensile strength provided by the matrix, and a high damping capacity provided by the second phase. A method of making the composite material involves mixing a powdery matrix material and a powdery second phase material, and then heat and consolidating the mixture at a temperature of 400 to 700 ° C. and a pressure of 100 to 300 MPa.

Abstract: There is provided a powder for permanent magnet comprising needle-like fine particles of Fe or Fe—Co alloy as a base material, a hard magnetic layer and a separation layer of an oxide of rare earth element provided outside said hard magnetic layer.

Abstract: A metal-matrix diamond or cubic boron nitride composite and method of making the same are disclosed. The metal-matrix/diamond composite includes grains of diamond uniformly distributed in a metal matrix. Alternatively, grains of cubic boron nitride may be used. Suitable metals for the metal matrix material may include nickel, cobalt, iron, and mixtures or alloys thereof. Other transition metals also may be used. The metal-matrix/diamond or metal-matrix/cubic boron nitride composite has high fracture toughness due to its fine microstructure. Such a metal-matrix/diamond or metal-matrix/cubic boron nitride composite is suitable for use in blanks or cutting elements for cutting tools, drill bits, dressing tools, and wear parts. It also may be used to make wire drawing dies.

Abstract: A hydrogen storage material is disclosed with no collapse due to pulverization of hydrogen storage alloy particles by repeated hydrogen absorption and desorption thereby permitting repeated use while manifesting excellent electric and thermal conductivities. Pressure molding of hydrogen storage alloy particles, each being covered with a plated metal film having microgranules of a thermoplastic resin, at a temperature higher than a glass transition temperature or a melting point of and below a thermal decomposition temperature of the thermoplastic resin can produce a porous hydrogen storage material of hydrogen storage alloy particles being bonded to each other via the thermoplastic resin. The hydrogen storage material can become firm and strong because the plated metal films covering the hydrogen storage alloy particles are clasped with each other complexly.

Abstract: The present invention intends to provide an iron-based powder composition for powder metallurgy having excellent flowability at room temperature and a warm compaction temperature, having improved compactibility enabling lowering ejection force in compaction, to provide a process for producing the iron-based powder composition, and to provide a process for producing a compact of a high density from the iron-based powder composition. The iron-based powder composition comprises an iron-based powder, a lubricant, and an alloying powder, and at least one of the iron-based powder, the lubricant, and the alloying powder is coated with at least one surface treatment agent selected from the group of surface treatment agents of organoalkoxysilanes, organosilazanes, titanate coupling agents, fluorine-containing silicon silane coupling agents.

Abstract: Disclosed is a method of shaping powdered metal parts comprising: (a) providing powdered metal from a source; (b) applying a heated fugitive coating to the powdered metal; (c) passing the powdered metal through a heated tube from a supply thereof to the die for the molding of the part; (d) monitoring the temperature of the heated tube during the passage of the powdered metal there through; (e) heating the die and monitoring the temperature thereof; (f) heating a punch die and monitoring the temperature thereof; (g) after filling the die with coated powdered metal, compacting the powdered metal by applying pressure from the punch die to the filled die thereby compacting the metal to a desired shape.

Abstract: Improved methods for coating particulate materials at low shear conditions and preferably below the melting point of the coating material are provided. In one aspect, metallurgical compositions are provided that contain a metal-based powder bound to an alloying powder or powders by way of a low melting polymer or wax binding agent, which is preferably polyethylene. The binding agent is blended with the metal-based and alloying powders at elevated temperatures preferably below the melting point of the binding agent. The bonded metallurgical composition can be used in compaction processes to manufacture compacted parts that can be sintered to impart strength.

Abstract: A process for producing a shaped article, comprising: preparing a first powder having high strength and rigidity after completion of forming, and a second powder having abrasion resistance and surface hardness after completion of forming; compacting those powders to provide a forming material comprising a base part comprising the first powder and a supplemental part comprising the second powder; and forming the forming material into a shaped article by plastic processing, thereby producing a shaped article in which the base part and the supplemental part have different characteristics. The first powder preferably comprises a rapidly-solidified alloy powder and the second powder preferably comprises at least one member selected from among Al2O3, Si3N4, BN, SiC, Al4C3, Al8B2O15 and B2O or a mixture of the member and the first powder which may be the same one actually used as the first powder or another one having a different compositions from that of the actually used first powder.

Abstract: The present invention relates to a sintered cemented carbide consisting of 50 to 90 wt-% submicron WC in a hardenable binder phase. The binder phase comprises, in addition to Fe, 10-60 wt-% Co, <10 wt-% Ni, 0.2-0.8 wt-% C, Cr, W, Mo and/or V in amounts satisfying the relations 2xC<xW+xCr+xMo+xV<2.5xC where x denotes mol fraction elements in the binder phase and the following relation for the total Cr content 0.03<wt-% Cr/(100-wt-% WC)<0.05 In addition, the binder phase consists of martensite with a fine dispersion, a few percent, of coherent carbides, preferably of M2C type, with a size of the order of 10 nm.

Abstract: The invention is directed to a method of forming parts having complex geometries made by coating ferrous based powders with a metallurgical coating, pressing the powder to make the parts, and using a low temperature heating step to diffuse the coating into the ferrous based powders.

Abstract: The application of polypropylene carbonate in solution to valve metal powders having relatively high surface area, then evaporating the solvent under static (non-agitating) conditions. The static drying of the coated valve metal powder produces a semi-solid cake which may be converted into a free-flowing powder via screening. Valve metal powders so-coated with polypropylene carbonate are particularly well-suited for the fabrication of powder metallurgy anode bodies used for the manufacture of electrolytic capacitors.

Abstract: The present invention relates to a method of making a cemented carbide comprising WC, 6-12 wt. % Co and 0.1-0.7 wt. % Cr, wherein the WC-grains are coated with Cr prior to mixing and no milling takes place during the mixing step. As a result a cemented carbide with improved properties is obtained.

Abstract: As there is disclosed a cemented carbide body comprising WC with an average grain size of <10 &mgr;m in a binder phase. In the cemented carbide body the WC grains can be classified in at least two groups in which a group of smaller grains has a maximum grain size amax and a group of larger grains has a minimum grain size bmin and each group contains at least 10 % of the total amount of WC grains. According to the invention bmin−amax>0.5 &mgr;m and the difference in grain size within each group is >1 &mgr;m.

Abstract: The object of the present invention is to provide rare-earth system sintered magnets such as R—Fe—B system or R—Co system having excellent magnetic properties, unique configuration of a small size, thin wall thickness and intricate geometry. With the method for preparing the present invention, a granulation of alloy powders can be achieved easily, a chemical reaction between rare-earth system and binder substances can be suppressed, so that the residual oxygen and carbon levels in the sintered products can be reduced. Moreover, by this production method, the flowability and lubricant capability during the forming process can be improved. The dimension accuracy and productivity are also enhanced. A certain type of binder is added to rare-earth alloy powders and kneaded into a slurry state. The slurry is then formed into granulated powders by spray-dryer equipment. The thus granulated powders are molded, and sintered through a powder metallurgy technique.

Abstract: A method for producing high-density powder metallurgy articles formed of hard powder materials, and particularly hard ferromagnetic materials that yield powder metallurgy magnets exhibiting improved magnetic properties as compared to powder metallurgy magnets formed of pure iron. The method generally entails the use of a powder of a material that is harder than iron, and then encapsulating each particle of the powder with a layer of iron. The powder is then compacted, by which the particles are adhered together to form a powder metallurgy article. As a result of forming a sufficiently thick encapsulating layer of iron on each powder particle, the powder can be compacted to a greater density than would be possible without the encapsulating layer of iron. If a ferromagnetic material is used, the resulting magnetic article is capable of exhibiting magnetic properties superior to a substantially identical pure iron powder metallurgy magnet.

Abstract: A method of making a potassium-doped tungsten powder is described comprising forming a mixture of ammonium paratungstate or ammonium metatungstate and a potassium-containing compound selected from a thermally unstable potassium-containing salt or a potassium tungstate, and reducing the mixture in a single step without adding additional dopants to form a potassium-doped tungsten powder. The potassium-doped tungsten powder produced by the method of this invention can be pressed, sintered and drawn to produce a non-sag tungsten wire.

Abstract: An iron-based powder composition is produces in accordance with a method comprising the steps of: adding to iron-based and alloying powders, for a primary mixing, a surface treatment agent, and in addition, for a secondary mixing, a fatty acid amide and at least one lubricant, wherein the lubricant has a melting point higher than that of the fatty acid amide and can be, a thermoplastic resin, a thermoplastic elastomer, and inorganic or organic compounds having a layered crystal structure; heating and stirring up a mixture after the secondary mixing at a temperature above a melting point of the fatty acid amide to melt the fatty acid amide; cooling, while mixing, the mixture subjected to the heating and stirring process so that the alloying powder and a lubricant having a melting point higher than the fatty acid amide adhere to a surface of the iron base powder subjected to the surface treatment by an adhesive force of the melt; and adding at the time of the cooling, for a tertiary mixing, a metallic soap and

Abstract: A method of forming a coating on metal particles that can be used to produce powder metallurgy articles, including those for electromagnetic and structural applications. The method is generally a solution-blending process that employs a coating solution that contains a solvent and one or more particulate additives, at least one of which is a polymeric binder that is only partially soluble in the solvent. As a result, only a portion of each binder particle is dissolved in the solvent. Notably, the coating solution is free of a discrete adhesion-promoting (tackifier) additive for adhering the polymeric binder to the metal particles. Instead, each binder particle is sufficiently dissolved in the solvent to promote adhesion of the binder particles to the metal particles during mixing, so that each metal particle is encapsulated with a coating containing the polymeric binder. The particles may then be compacted to bind them together with the coating and form a solid article.

Abstract: The invention provides techniques for forming composites including XW.sub.2 O.sub.8, where X=Zr, Hf, or a combination, dispersed within a continuous, metal matrix. A low to zero coefficient of thermal expansion material, with high thermal and electrical conductivity, results. One method for forming the composite involves coating particles of XW.sub.2 O.sub.8 with a layer of metal, then isostatically pressing the particles under conditions amenable to formation of a composite. The technique of coating, with a more malleable phase, a phase that undergoes a disadvantageous phase transformation of decomposition upon exposure to a threshold pressure at a set temperature can be applied to a variety of materials.

Abstract: It has been discovered that potassium retention in NS tungsten processing may be improved by double doping tungsten blue oxide (TBO) prior to reduction. The novel `double-doping` process consists of dry doping standard singly doped K--Al--Si TBO with potassium nitrate, KNO.sub.3, followed by the standard reduction, acid washing, sintering, rolling and drawing steps. In another aspect, the novel method includes an aqueous extraction of heteropolytungstate anion [SiW.sub.11 O.sub.39 ].sup.8- from a sample of the singly doped tungsten blue oxide to predict potassium retention.

Abstract: A composite structure and method for manufacturing same, the composite structure being comprised of metal particles and an inorganic bonding media. The method comprises the steps of coating particles of a metal powder with a thin layer of an inorganic bonding media selected from the group of powders consisting of a ceramic, glass, and glass-ceramic. The particles are assembled in a cavity and heat, with or without the addition of pressure, is thereafter applied to the particles until the layer of inorganic bonding media forms a strong bond with the particles and with the layer of inorganic bonding media on adjacent particles. The resulting composite structure is strong and remains cohesive at high temperatures.

Abstract: The present invention includes iron-carbon compacts and a process for making them. The process includes preparing a slurry comprising iron powder, furfuryl alcohol, and a polymerization catalyst for initiating the polymerization of the furfuryl alcohol into a resin, and heating the slurry to convert the alcohol into the resin. The resulting mixture is pressed into a green body and heated to form the iron-carbon compact. The compact can be used as, or machined into, a magnetic flux concentrator for an induction heating apparatus.

Abstract: A method for forming molded articles in any shape from ceramic, glass, or metal powders which comprises: preparing a slurry by dispersing more than one powder selected from a group consisting of ceramic, glass, and metal materials in a dispersing medium using a dispersing agent, and curing by adding a reactive substance that reacts with the dispersing agent to make the dispersibility of the dispersing agent disappear or lower.

Abstract: Novel processes for fabricating metal matrix composites consisting of discontinuous reinforcing particles in a metal matrix are described. In one aspect, reinforcing particles are coated with a metal matrix material by means of chemical vapor deposition using a volatile metal-containing compound, followed by consolidation of the metal-coated particles. In another aspect, reinforcing particles are coated with a metal matrix material by means of electrochemical deposition of a metal, followed by consolidation of the metal-coated particles. In yet another aspect, reinforcing particles coated with a metal matrix material by one of the aforesaid methods are blended with metal or alloy particles not containing such reinforcement, then consolidated.

Abstract: A powder of composite particles is prepared by adhering to the surfaces of particles of an amorphous magnetically soft alloy particles of a glass having a softening point lower than the crystallization temperature of the alloy to coat the surfaces of the alloy particles with the glass. The powder of composite particles prepared is pressed at a temperature higher than the softening point of the glass and lower than the crystallization temperature of the alloy to bond the alloy particles with the glass. The pressed powder body is at least 0.5 in the ratio of the magnetic permeability at 10.sup.7 Hz to the magnetic permeability at 10.sup.4 Hz.

Abstract: A metallic composite solid, containing alloys and/or intermetallics, is formed by compacting at moderate pressure a mixture of powder particles, foils or sheets at a temperature close to room temperature, well below the melting temperature of the constituent components and without the addition of low melting metals such as mercury, indium or gallium acting as a sintering agent. This low temperature consolidation of the powder mixture is enhanced by having the surface oxide of the powder particles removed, prior to consolidation, and/or by coating the particles with an oxide-replacing metal such as silver or gold. The coating process may be replacement reactions, autocatalytic reduction or electrolytic reduction. The composite formation is assisted by the addition of a liquid acid such as fluoroboric acid, sulfuric acid, fluoric acid, adipic acid, ascorbic acid, or nitric acid.

Abstract: Post-compaction treatments of iron compacts to improve the mechanical strength of the compacts are provided. Powder is compacted into the desired part. The part is then subjected to a strengthening operation. This operation involves a heat treatment at a moderate temperature combined with an optional resin impregnation. The heat treatment is done at a temperature sufficient to increase the mechanical properties of the compact while maintaining the magnetic losses low for the required application. Impregnation with an insulating binder can be effected to increase the mechanical strength of the part without creating electric contacts between the powder particles.

Abstract: A sintered oil-impregnated bearing 20 used in a bearing device 30 is made by molding a mixture of a composite fine particles (main material) and a solid lubricant previously added to the main material in a proportion of about one weight percent to about three weight percent, wherein the main material comprises composite fine particles composed of iron powders having surfaces coated with copper, and the solid lubricant comprises fine particles made of an inorganic compound such as molybdenum disulfide and having surfaces coated with copper, sintering the mold at a temperature in a range of 650.degree. C. to 700.degree. C. to form a sintered body 20b, and impregnating the sintered body 20b with lubricant oil. Since the sintered body 20b itself has lubricity, the sintered oil-impregnated bearing is free from abrasion or seizure even if oil is used up.

Abstract: A tungsten skeleton structure fabrication method employed in an application of a copper infiltration and tungsten-copper composite fabrication method includes the steps of forming a source powder by coating the tungsten powder surface having a purity of 99.9 weight percent and 2.about.5 .mu.m in size, with nickel by less than 0.06 weight percent (600 ppm), forming an injection molded admixture by admixing a source powder and a polymer binder, carrying out a powder injection molded with regard to the admixture, and obtaining a tungsten skeleton structure by removing the polymer binder from the resultant injection molded body. The method prevents the molded body from being unevenly shrunken during a liquid phase sintering for thereby decreasing its production cost.

Abstract: In the present invention, nickel and phosphorous are simultaneously plated onto the surface of iron powder, mixed iron and nickel powder, or iron-nickel pre-alloyed powder, to form iron-nickel-phosphorous ternary alloy powders with very uniform distribution of phosphorous, with concentrations ranging between 2.0 and 6.0 wt%. When mixed with an appropriate amount of organic binder, these powders may be used as raw materials for injection molding. Intricate parts thus formed can be sintered at relatively low temperatures to attain high sintered density, large grain size, and isotropic shrinkage. The sintered microstructure thus obtained is characterized by spheroidal grains embedded in continuous intergranular insulating phosphide phase. The magnetic properties of the resulting material are substantially improved as compared to those of powder processed products.

Abstract: A laminated composite structure of alternating metal powder layers, and layers formed of an inorganic bonding media powder, and a method for manufacturing same are discosed. The method includes the steps of assembling in a cavity alternating layers of a metal powder and an inorganic bonding media of a ceramic, glass, and glass-ceramic. Heat, with or without pressure, is applied to the alternating layers until the particles of the metal powder are sintered together and bonded into the laminated composite structure by the layers of sintered inorganic bonding media to form a strong composite structure. The method finds particular application in the manufacture of high performance magnets wherein the metal powder is a magnetic alloy powder.

Abstract: The present invention relates to a thermoelectric material containing CoSb.sub.3 compound for converting heat to electricity, and provides a p-type thermoelectric material of CoSb.sub.3 having a high power factor by achieving high Seebeck coefficient consistently with high electric conductivity in a material of CoSb.sub.3 system without causing increase in heat conductivity. By sintering Co.sub.0.07 Pt.sub.0.03 Sb.sub.3 alloy powder using the spark plasma sintering technique, the material is densified, while growth of grains is restricted, so that a higher electric conductivity is achieved with a heat conductivity maintained in a low level, and the figure of merit as a heat-transfer material is improved. Also, by providing such heat insulating layer as an oxide intermediately in a grain boundary of a compound of CoSb.sub.3 in a sintered body, the heat conductivity is reduced. Further, the Seebeck coefficient is increased by adding a rare earth metal to the thermoelectric material of CoSb.sub.

Abstract: A process of molding inorganic materials into desired shapes comprises mixing the material with a dispersant, milling, molding the mixture, drying the mixture and sintering.

Abstract: There is now provided a roll for hot rolling comprising 70-95 weight %, preferably 85-94 weight %, WC in a binder phase consisting of only cobalt or alternatively a Co--Ni--Cr alloy containing 20-35 weight % Ni and up to 10 weight % Cr, possibly with small additions of molybdenum. The WC grains are rounded with an average grain size between 3-10 .mu.m, preferably 4-8 .mu.m. The maximum grain size should not exceed 2 times the average grain size and no more than 2% of the grains be less than half of the average grain size.

Abstract: A method of making a hard constituent powder coated with Co and/or Ni in a solution by liquid reduction of the Co and/or Ni from a suitable metal compound with a polyol while keeping the powder in suspension, the polyol functioning both as a solvent and as a reducing agent at the same time. By separating the intermediate solid compound and hard constituent from the suspension before any by-products are formed and reducing the intermediate solid compound in the dry state by H.sub.2 for around 24 hours or by using an excess of about 10 times more moles polyol than moles metal, the polyol can be conserved or reused leading to improved cost efficiency of the process.

Abstract: A sintered body having diamond grains dispersed and held in a matrix of cemented carbide or cermet is obtained by direct resistance heating and pressurized sintering. The sintering is performed at a liquid phase generating temperature in a short time, so that the diamond grains are not directly bonded to each other. Thus, a superhard composite member that has excellent hardness and wear resistance can be obtained without employing an ultra high-pressure vessel.

Abstract: One or more metal salts of at least one of Co, Ni and/or Fe is dissolved/suspended in water. To the solution/suspension is added at least one hard constituent powder to form a slurry. The solvent is evaporated, preferably by spray drying, and the resultant powder is heat treated in a reducing atmosphere. As a result, a coated hard constituent powder is obtained which, after addition of a pressing agent, can be compacted and sintered according to standard practice. In addition to or instead of said salt of Co, Ni and/or Fe, a soluble salt of Mo and/or W can be used.

Abstract: A method of making a hard constituent powder coated with at least one iron group metal, Me, by dissolving and complex binding at least one of Me.sub.n (NO.sub.3).sub.m and Me.sub.n (SO.sub.4).sub.m and other similar Me.sub.n --X.sub.m compounds containing X-groups with low or no carbon content, preferably Me-nitrates, solely or together with one or more metal salts of at least one iron group metal containing organic groups in at least one polar solvent with at least one complex former comprising functional groups in the form of OH or NR.sub.3, (R=H or alkyl). Hard constituent powder is added to the solution. The solvent is evaporated and remaining powder is heat treated in an inert and/or reducing atmosphere. As a result, coated hard constituent powder is obtained which after addition of a pressing agent can be compacted and sintered according to standard practice.

Abstract: This patent application discloses a new process for preparing the sintered article of aluminum nitride at low temperature. It comprises coating aluminum metal film on aluminum nitride powder, then directly molding or homogeneously cold pressing, followed by sintering at 1650.about.175O.degree. C., and finally forming dense aluminum nitride article.