Abstract: The present invention provides metal-based composite with oxide particle dispersion and a method for producing the same.The present invention relates to a method for producing metal-based composite with oxide particle dispersion, comprising sintering of metal-based ultrafine powders (with an average grain size of about 20 nm to 100 nm and a grain size distribution of about 5 nm to 300 nm and with the surface oxidized for handling) in vacuum, in an inert gas or in a reducing atmosphere by rapid sintering, crystallizing the ultrafine powders with a grain size of about 50 nm or less to metal oxide during sintering and simultaneously removing the oxygen on the surface of the ultrafine powders with the grain size of about 50 nm or more, and the metal-based composite with oxide particle dispersion produced according to the said method.

Abstract: Carbon fluoride particles in which a number-average particle size is 0.01 to 50 .mu.m, a content of particles having such a diameter that the particles size distribution falls with in range of the number-average particle size .+-.20% amounts to at least 50% of the whole, a true specific gravity is 1.7 to 2.5, a F/C as a whole is 0.001 to 0.5, and a F/C at the surface is always larger than the F/C as a whole and is 0.1 to 2.0. These carbon fluoride particles are obtainable by reacting carbon particles with fluorine at 350.degree. to 600.degree. C. for one minute to six hours.

Abstract: The present invention relates to an improved method of manufacturing an airbag initiator. Currently, an airbag initiator is comprised of three parts made out of two dissimilar materials plus a glass to metal seal. The present method builds the same airbag initiator with the body and the pins in one piece via a process called metal injection molding. The part is then placed in a furnace to remove a wax binder, then the temperature is ramped up slowly to remove a thermoplastic layer, and the temperature is further ramped up to form a sintered part. The sintered part being equal to or better than standards of wrought material. The initiator is then removed from the furnace and a glass bead is placed in a void area in the body of the initiator. The glass is melted forming a glass to metal seal between a first pin and the body of the initiator. A top portion of the initiator is then lapped off isolating the first pin from the body of the initiator.

Abstract: An improved metal matrix composite which, in a preferred embodiment disclosed herein, utilizes boron carbide as the ceramic additive to a base material metal. The metal matrix composite of the present invention begins with the preparation of the boron carbide powder by particle size selection in a jet mill. The resulting powder and metal powder are then mixed by blending of powder of all the various elements such as by means of a conventional blender to uniformly mix powdered substances and avoid stratification and settling. After the particles have been sufficiently mixed, they are degassed and then placed into a die and then into a cylindrical container where the particulates are subjected to extremely high pressures transforming the elements into a solid ingot. It is from these ingots that the extrusion tubes or other articles of manufacture may then be made.

Abstract: A compacted, single phase or multiphase composite article. Particles for use in the compacted article are produced by providing a precursor compound containing at least one or at least two metals and a coordinating ligand. The compound is heated to remove the coordinating ligand therefrom and increase the surface area thereof. It may then be reacted so that at least one metal forms a metal-containing compound. The particles may be consolidated to form a compacted article, and for this purpose may be used in combination with graphite or diamonds. The metal-containing compound may be a nonmetallic compound including carbides, nitrides and carbonitrides of a refractory metal, such as tungsten. The metal-containing compound may be dispersed in a metal matrix, such as iron, nickel or cobalt. The dispersed nonmetallic compound particles are no larger than about 0.1 micron in particle size and have a volume fraction greater than about 0.15 within the metal matrix.

Abstract: This invention, using finely ground powders obtained by either a ingot grinding method, a Ca reduction diffusion method or a strip casting method, proposes a fabrication method for high-performance R--Fe--B permanent magnets with excellent press packing characteristics, a high degree of orientation of the magnetization direction of each crystallite and a total sum of A, (BH)max (MGOe) and B, iHc (kOe), A+B greater than 59.5. Here, cast alloys or ground alloys are coarse ground by mechanical grinding or by a H.sub.2 absorption and decomposition method, and then fine ground by either mechanical grinding or by a jet mill grinding process to yield R--Fe--B fine powders with an average particle size of 1.0 .mu.m.about.10 .mu.m. These powders are then packed into a mold at a packing density of 1.4.about.3.5 g/cm.sup.

Abstract: There is provided a sintered titanium-based carbonitride alloy for metal cutting containing hard constituents based on Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and/or W and 3-30% binder phase based on Co and/or Ni. The structure contains 10-50% by weight well-dispersed Ti-rich hard constituent grains essentially without core-rim structure with a mean grain size of 0.8-5 .mu.m in a conventional carbonitride alloy matrix with a mean grain size of the hard constituents of 1-2 .mu.m. The Ti-rich hard constituent grains are essentially rounded, non-angular grains with an approximately logarithmic normal grain size distribution with a standard deviation of <0.23 logarithmic .mu.m.

Abstract: The porous metal body of the inventtion has a porosity of 7 to 50%, pore sizes of 1 to 500 .mu.m and a pore distribution satisfying the relationship of:(D.sub.95 -D.sub.5)/D.sub.50 .ltoreq.2.5wherein D.sub.5 is the pore size on the cumulative distribution curve of the pore sizes at a cumulative frequency of 5%, D.sub.50 is the pore size on the curve at a cumulative frequency of 50% and D.sub.95 is the pore size on the curve at a cumulative frequency of 95%. The porous body is improved in porosity characteristics and mechanical strength.The porous metal body is prepared by pressing a metal powder to shape and sintering the shaped body by hot isostatic pressing, or alternatively by enclosing a metal powder in a capsule, subjecting the encapsulated powder to a primary sintering treatment in an isostatic medium to form a primary sintered porous body and heat-treating the sintered body with the capsule removed or without removing the capsule.

Abstract: Metallurgical powder compositions are provided which contain a metal powder in admixture with a solid, particulate polyether lubricant. The incorporation of the polyether lubricant enhances the green strength properties of compacted parts made from the powder compositions, and generally reduces the ejection forces required to remove the compacted part from the die cavity.

Abstract: Enhancement of mechanical properties of ceramic membranes by introduction of a uniformly distributed high-temperature oxidation-resistant metal phase into the brittle ceramic phase to achieve mechanically strong ceramic/metal composites operable in an oxidation atmosphere and at elevated temperatures.

Abstract: The invention relates to the manufacture of paper machine roll shells of stainless steel. According to the invention, powder is made of molten steel by gas-atomizing, a roll shell preform is made of the powder, and the roll shell preform is machined to form a roll shell. The main advantage of the rolls shells according to the invention is their good corrosion fatigue resistance.

Abstract: A ceramic capacitor suitable for high energy density and high temperature application is disclosed. Such a capacitor is prepared by producing the selected ceramic powder via the sol-gel process forming the capacitor to the desired shape with the resulting powder using tape casting technology and firing the "green" form so produced.

Abstract: Process for producing very pure platinum materials dispersion-reinforced with Y.sub.2 O.sub.3 and having high strength and extensibility, even in the temperature range >800.degree. C., from platinum powder by mechanical alloying, which comprises the process stepspreparing platinum powder of high purity and low particle size of from 2 to 10 .mu.m,introducing and dispersing Y.sub.2 O.sub.3 particles >1 .mu.m in the platinum powder by milling in a platinum vessel using milling media of zirconium oxide,degassing the milled product under a vacuum of better than 10.sup.-3 mbar and with an increase in temperature to at least 1200.degree. C. in a platinum capsule for a period of up to 48 hours,gastight welding of the evacuated capsule and hot isostatic pressing at 1350.degree. C.

Abstract: Metal silicide targets are provided for sputtering which have a density of at least 99%, no more than one coarse silicon phase 10 .mu.m or larger in size that appears, per square millimeter, on the sputter surface, and an oxygen content of at most 150 ppm. They are made by a method which comprises finely grinding a synthesized silicide powder, vacuum annealing the finely ground powder in a hot press die without the application of pressure, and thereafter compacting and sintering the compact to a density of at least 99% by hot pressing. Alternatively, the finely ground powder is vacuum annealed as a presintered body at a density ratio of 50 to 75%, and thereafter is compacted and sintered.

Abstract: A process for preparing an alloy having excellent corrosion resistance and abrasion resistance is provided. The alloy is prepared by providing a powder mixture or VC-powder-containing wire having a matrix metal, including a VC powder having a particle diameter of 10 .mu.m or less, and at least one member selected from the group consisting of an Fe-base alloy, a Co-base alloy and a Ni-base alloy. The powder mixture or VC-powder-containing wire is melted with a heat source having a high energy density. The resultant melt is then cooled to homogeneously crystallize and/or precipitate VC, such that the particle diameter of the VC is reduced to 5 .mu.m or less in the matrix metal phase. Also disclosed is a process for preparing a surface-modified metallic member from a metallic member and an alloy prepared from the aforementioned process.

Abstract: A high density metal component manufactured by powder metallurgy is disclosed. The powder metallurgy method provides metal components having a density greater than 95% of theoretical density using a single sequence of uniaxial pressing and heating. The metal components are manufactured from substantially linear, acicular metal particles having a substantially triangular cross section.

Abstract: A brazeable aluminum material is composed of an aluminum core and a brazing agent layer consisting of a brazing agent thermally sprayed onto covering a surface of the core. A number of unmolten minute particles of the brazing agent are present in the brazing agent layer, which contains at least an aluminum-silicon alloy and/or a mixture of aluminum and silicon. Characteristic features of a method of producing the brazeable aluminum material are the steps of: preparing a powder composed of minute particles; and thermally spraying the powder onto the aluminum core in such a state that only a surface of each minute particle is molten, with a pith of the particle remaining unmolten. The powder is an Al-Si alloy and/or a mixture of Al powder and Si powder.

Abstract: A composite material is disclosed along with the method of making the same. The material comprises a tough grade of cemented carbide granule dispersed with a hard brittle grade of cemented carbide granules to form a matrix. The quantity of hard, brittle cemented carbide granules is between 20% to 60% of the total composition. Such material functions to improve wear resistance without sacrificing toughness.

Abstract: According to the invention there now is provided a method of producing a sintered titanium based carbonitride alloy with 3-25 weight % binder phase with extremely good properties at intermittent machining of materials difficult to machine. The method relates to the use of a raw material comprising a complex cubic carbonitride containing the main part of the metals from groups IV and V of the periodic system and carbon and nitrogen to be found in the finished alloy whereby said alloy has the composition0.86.ltoreq.X.sub.IV .ltoreq.0.970.44.ltoreq.X.sub.C .ltoreq.0.55where X.sub.IV is the molar ratio of the group IV elements of the alloy and X.sub.C is the molar ratio of carbon.

Abstract: Particles of metal alloys and composites have been developed that are particularly suitable for use in producing thixotropic alloys and in the injection molding of such alloys. The particulate material comprises particles of metal alloy or composite, wherein a substantial proportion of the particles is shaped such that the ratio of the length of the largest dimension of a particle to the effective diameter of the particle is in the range of 1.0 to 4.0 and the substantial proportion of particles has a particle size wherein the largest dimension of the particles lies within the range of 0.5 to 5.0 mm. This allows convenient handling of the particles whilst also avoiding binding or clogging of the screw, in the case where a screw extruder is used.

Abstract: A metal casing for a semiconductor device is manufactured by a powder metallurgy injection molding process which uses infiltration. The metal casing includes a base member and an enclosure member arranged on the base member. The base member and the enclosure member are formed of an alloy including 20 to 50 percent by volume of copper, equal to or less than 1 percent by weight of nickel and remainder of tungsten or molybdenum. The metal casing is manufactured as a net-shape product by a process which includes the steps of mixing tungsten powder and nickel powder having average particles sizes equal to or less than 40 .mu.

Abstract: According to the invention there now is provided a method of producing a sintered titanium based carbonitride alloy with 3-25 weight-% binder phase with extremely good properties at semifinishing operations at turning. The method relates to the use of a raw material consisting of a complex cubic carbonitride comprising the main part of the metals from groups IV and V of the periodic system and carbon and nitrogen to be found in the finished alloy whereby said alloy has the composition0.85.ltoreq.X.sub.IV .ltoreq.0.990.58.ltoreq.X.sub.C .ltoreq.0.69where X.sub.IV is the molar ratio of the group IV elements of the alloy and X.sub.C is the molar ratio of carbon.

Abstract: According to the invention there now is provided a method of producing a sintered titanium based carbonitride alloy with 3-25 weight-% binder phase with extremely good properties at fine to medium coarse milling. The method relates to the use of a raw material consisting of a complex cubic carbonitride comprising the main part of the metals from groups IV and V of the periodic system and carbon and nitrogen to be found in the finished alloy whereby said alloy has the composition0.89.ltoreq.X.sub.IV .ltoreq.0.970.52.ltoreq.X.sub.C .ltoreq.0.61where X.sub.IV is the molar ratio of the group IV elements of the alloy and X.sub.C is the molar ratio of carbon.

Abstract: A method of preparing a metal alloy product from a powder blend. The method comprising: (a) cold pressing a blend to form a compact, the metal blend comprising a metal powder phase and at least one reinforcement phase having a hardness greater than the metal phase; (b) heating the compact to form a preheated compact; and (c) hot working the heated compact. In a preferred method, the powder metal blend comprises 50 to 90 vol. % of an aluminum alloy powder and 10 to 50 vol. % of silicon carbide; the heating of the compact perforated in a nitrogen atmosphere to form a preheated compact; and the extruded hot compact is hot worked. Hot working may take the form of forging, rolling, upset forging, exuding, compacting or other processes known in the art.

Abstract: According to the invention there now is provided a method of producing a sintered titanium based carbonitride alloy with 3-25 weight-% binder phase with extremely good properties at extreme fine machining when turning with high cutting rates. The method relates to the use of a raw material comprising a complex cubic carbonitride containing the main part of the metals from groups IV and V of the periodic system and carbon and nitrogen to be found in the finished alloy whereby said alloy has the composition0.86.ltoreq.X.sub.IV .ltoreq.0.990.74.ltoreq.X.sub.C .ltoreq.0.83where X.sub.IV is the molar ratio of the group IV elements of the alloy and X.sub.C is the molar ratio of carbon.

Abstract: This invention relates to a process of forming a sintered article of powder metal comprising blending graphite and lubricant with a pre-alloyed iron based powder, pressing said blended mixture to shape in a single compaction stage sintering said article, and then high temperature sintering said article in a reducing atmosphere to produce a sintered article having a density greater than 7.4 g/cc.

Abstract: A dispersion strengthened copper alloy and a method for producing the alloy are provided. The alloy preferably comprises aluminum, titanium and hafnium as alloying elements that are internally oxidized under controlled conditions to produce a dispersion strengthened copper material having good hardness and high conductivity. A method for reducing the adverse effects of hydrogen on such materials is also provided. The dispersion strengthened material can be useful in many applications, including welding electrodes and electrical contacts.

Abstract: A method of producing bearing surfaces from powder metal blanks comprising: blending carbon and ferro alloys and lubricant with compressible elemental iron powder, pressing the blending mixture to form the powder metal blank, high temperature sintering the blank in a reducing atmosphere, compressing the powder metal blanks so as to produce a densified layer having a bearing surface, and then heat treating the densified layer.

Abstract: Shot pellet or small arms projectile comprises 40-60% by weight of tungsten and 60-40% by weight of iron formed by sintering tungsten containing powders having median particle sizes below 6 microns to form a material consisting primary of an intermetallic compound of tungsten and iron or of a metal matrix of iron surrounding tungsten containing particles.

Abstract: A process of forming a sintered article for powder metal comprising blending carbon and ferro alloys and lubricant with compressible elemental iron powder, pressing said blended mixture to form sintering said article, and then high temperature sintering said article in a reducing atmosphere to produce a sintered article having a high density from a single compression.

Abstract: A process of coining sintered articles of powder metal comprising: blending carbon, ferro manganese, and lubricant with compressible elemental iron powder, pressing the blended mixture to form the articles, high temperature sintering of the articles in a reducing atmosphere and then coining the sintered articles to final shape so as to narrow the tolerance variability of coined articles and substantially eliminate secondary operations.

Abstract: A method of preparing dense sintered bodies of beta alumina suitable for solid electrolytes, which comprises preparing a shaped body from a mixture containing an aluminum powder, a sodium compound, a structure stabilizer and a zirconia powder or from a mixture containing an aluminum powder, an alumina powder, a sodium compound, a structure stabilizer and a zirconia powder, and reaction-sintering the shaped body.

Abstract: A process for forming an electrode assembled into a vacuum interrupter is composed of the steps of blending silver(Ag) powder and chromium(Cr) powder in a content ratio such that Ag powder forms a matrix and Cr powder being dispersed therein, the blending ratio is prefer to be determined to contain 50 to 95 wt. % of Ag powder and 5 to 50 wt. % of Cr powder, compacting the blended powder to a compacted body, sintering the body at temperatures around melting point of Ag, and regulating density of the sintered article at least 90%. Particle size of Cr to be blended may be determined less than 150 .mu.m, more preferably, less than 60 .mu.m. Sintering temperature may be determined between 800.degree. to 950.degree. C.

Abstract: A process of forming a sintered article of powder metal comprising: selecting elemental iron powder; determining the desired properties of said sintered article and selecting, a quantity of carbon, and ferro alloy from the group of ferro manganese, ferro chromium, ferro molybdenum, ferro vanadium, ferro silicon and ferro boron; grinding said ferro alloy to a mean particle size of approximately 8 to 12 microns; introducing a lubricant while blending the carbon, ferro alloy, with said elemental iron powder; pressing the mixture to form the article; and then high temperature sintering the article at a temperature between 1,250.degree. C. and 1,350.degree. C. in a neutral or reducing atmosphere; so as to produce the sintered article of powdered metal; and includes the product formed thereby.

Abstract: A sputtering target that consists essentially of a continuous matrix of Ti-W phase, Ti phase having a particle diameter of 50 .mu.m or less distributed in the matrix, and a W phase having a particle diameter of 20 .mu.m or less also distributed in the matrix. Preferably the target contains aluminum in the range of 1 ppm or less. The target has high density and a low impurity content, which reduces the generation of particles from the target when it is used for sputtering. A method of manufacturing the sputtering target is also disclosed.

Abstract: A process for fabrication of sintered metal components having improved mechanical, physical and wear-resistent properties.

Abstract: A method of manufacturing an Ni--Al intermetallic compound matrix composite comprising steps of a) providing an aluminum powder, b) providing a reinforced material, c) providing a reducing solution containing a reducing agent and nickel ions to be reduced, d) adding the aluminum powder and the reinforced material into the reducing solution, and e) permitting the reducing agent to reduce the nickel ions to be respectively deposited on the aluminum powder and the reinforced material. Such method permits the Ni--Al, Ni--Al+B intermetallic compound matrix composite to be produced inexpensively/efficiently/fastly.

Abstract: Silicide targets for sputtering which have an area ratio of silicon phases that appear on the sputter surface of no more than 23%, and a density of at least 99%, with a deformed layer partly removed from the surface to attain a surface roughness of from more than 0.05 .mu.m to 1 .mu.m, preferably with the number of coarse silicon phases at least 10 .mu.m in diameter that appear on the sputter surface being at most 10/mm.sup.2. The reduction of early-stage particle generation, in turn, reduces secondary particle generation, thus realizing the reduction of particle generation at both early stage and stabilized stage. A Si powder having a maximum particle diameter of no more than 20 .mu.m is mixed with a metal powder having a maximum particle diameter of no more than 60 .mu.m, in a rather Si-lower mixing ratio. A silicide powder is synthesized from the mixture and hot pressed, the sintered compact being machined and surface treated for the removal of the deformed layer.

Abstract: A fully dense ceramic-metal body including 40-88 v/o of an oxide hard phase of, in v/o of the body, 4-88 v/o M-aluminum binary oxides, where the binary oxide has a C-type rare earth, garnet, .beta.-MAl.sub.11 O.sub.18, or perovskite crystal structure, and M is a lanthanide or indium, and 0-79 v/o .alpha.-alumina; about 10-50 v/o of a hard refractory carbide, nitride, or boride as a reinforcing phase; and about 2-10 v/o of a dispersed metal phase combining Ni and Al mostly segregated at triple points of the microstructure. The preferred metal phase contains a substantial amount of the Ni.sub.3 Al ordered crystal structure. In the preferred body, the reinforcing phase is silicon carbide partially incorporated into the oxide grains, and bridges the grain boundaries. The body including a segregated metal phase is produced by densifying a mixture of the hard phase components and the metal component, with the metal component being present in the starting formulation as Ni powder and Al powder.

Abstract: The invention provides aluminum sintered alloys with high dimensional accuracy and high density which are superior in mechanical and physical characteristics as well as wear resistance, and a method of producing such alloys not by plastic working but by atmospheric sintering with high economy. Rapidly solidified aluminum alloy powder resulting from solidifying aluminum alloy molten metal containing 0.4 to 4.0% by weight of Mg at a solidification rate of 10.sup.2 .degree. C./sec or more is press molded in the cold, after annealing in the temperature range of 250 to 450.degree. C. if necessary, and then the molded product is sintered by generating nitrogen compounds on the powder surface at atmospheric pressure with a nitrogen partial pressure of 0.8 atm or more and a steam partial pressure of 0.01 atm or less in which a reducing gas component has been added as a nitrogen-combining acceleration gas component by 0.01 atm or more. Thus, a nitrogen-combined aluminum sintered alloy containing 0.4 to 4.

Abstract: A method for manufacturing an intermetallic compound comprises (a) preparing a powder, (b) canning said powder in a tube, (c) executing a first heat treatment to said tube-canned powder, and (d) treating said tube-canned powder for obtaining an intermetallic compound. This invention offers a simple, efficient, and inexpensive method for producing an intermetallic compound possessing excellent mechanical properties.

Abstract: A method for manufacturing a metal graphite brush comprises steps of preparing natural graphite powders of 60-70 wt %, electrolytic copper powders of 30-40 wt %, molybdenum disulfide and lead of 2.5 wt % and the mixed resin of novolak phenol resin and furfural resin powders of 1-15 wt % which are adhesives, wet-mixing graphite powders with adhesives, pulverizing mixed powders to diameters of less than 200 .mu.m, press-molding all the powders under a pressure of 2-3 ton/cm.sup.2 and heating at a temperature 700.degree. C., and attaching a lead wire thereto, simultaneously, wherein the average particle distribution of the powders is 27 .mu.m. The compound ratio of graphite powders: copper powders: molybdenum disulfide: lead is 62.5 wt %: 35 wt %: 1.5 wt %: 1.0 wt %, the adhesives comprising the mixed resin of novolak phenol resin and furfural resin by 50:50 is added by a weight ratio of 7.5 wt % to the graphite powders.

Abstract: Complex-shaped parts can be produced from powders, for example metal-matrix composites, by injection molding using a mixture of the powders with a suitable binder. The binder must be removed from the powder mixture before the final thermal treatment of the so-called green part. The present invention proposes to remove the binder by surrounding a cast part with a layer of a particulate material and to subject the cast part to isostatic pressure through the surrounding layer which can thus act as an absorbent. The surrounding layer is removed after the isostatic pressing and the part can be subjected to sintering. The method is suitable for example for aluminum-ceramic powder mixtures.

Abstract: A dimensionally stable hydride composition and a method for making such a composition. The composition is made by forming particles of a metal hydride into porous granules, mixing the granules with a matrix material, forming the mixture into pellets, and sintering the pellets in the absence of oxygen. The ratio of matrix material to hydride is preferably between approximately 2:1 and 4:1 by volume. The porous structure of the granules accommodates the expansion that occurs when the metal hydride particles absorb hydrogen. The porous matrix allows the flow of hydrogen therethrough to contact the hydride particles, yet supports the granules and contains the hydride fines that result from repeated absorption/desorption cycles.

Abstract: The method of making the casing comprises the steps of preparing a powder mixture consisting predominantly of a metal powder mixed with a minor proportion of graphite powder ranging from about 0.2% to about 2%, preferably 0.8% by weight, while the metal powder ranges from about 99.8% to about 98% by weight. The powder material is compressed into a casing mold to a molded density ranging from about 0.21 to about 0.24, preferably 0.23 of a pound per cubic inch. The molded powder is sintered in an inert atmosphere at a temperature ranging from about 1500 to about 1700, preferably 1600.degree. F. for a time sufficient to unite the molded powder into a brittle porous frangible casing. The graphite powder vaporizes and escapes from the molded casing during the sintering step whereby porosity and frangibility are imparted to the casing.

Abstract: The present invention relates to a method of producing a sintered body comprising one or more hard constituents and a binder phase based on cobalt, nickel and/or iron by powder metallurgical methods milling, pressing and sintering of powders. At least part of the binderphase powder consists of non-agglomerated particles of spheroidal morphology having dimensions of 0.1 to 20 .mu.m.

Abstract: In a method for preparing a high .alpha.-type silicon nitride powder by adding to and mixing with metallic silicon powder a copper catalyst and nitriding the mixture in a non-oxidizing gas atmosphere containing nitrogen or ammonia at 1,000.degree. to 1,500.degree. C., the amount of copper catalyst is limited to from 0.05 % to less than 0.5 % by weight of copper based on the weight of the metallic silicon. There is obtained silicon nitride powder of high purity at low cost and high efficiency since the copper catalyst can be efficiently removed from the silicon nitride powder through conventional acid treatment.

Abstract: Brazed structures are disassembled with little or no physical damage to the components by coating the brazed joints with a powdered wicking agent, preferably mixed with a fugitive liquid binder to form an adherent slurry, then heating the joint to allow the brazing alloy to melt and be drawn into the powdered wicking agent by capillary action. After cooling, the powder and braze alloy are mixed together to form a loosely consolidated mass which can be readily removed by mechanical and/or chemical means so that the components can then be separated for repair or reuse.

Abstract: A porous living body repairing member obtained by compression-molding a metal fiber material into a desired shape, sintering the fiber mesh body or thereafter, and imparting a compressive stress of not more than 4.00 to 40.0 MPa to provide a porous living body repairing member having a compressive elasticity of not more than 2000 MPa and a permanent deformation of not more than 1% under a stress below a compressive yield stress.The compressive yield stress becomes approximately equal to the above compressive stress, and almost complete elasticity of a permanent deformation rate of not more than 0.1% is shown with respect to a compressive stress below this compressive yield stress. Accordingly, even when the porous living body repairing member is used at a high compressive load site such as man's lumbar body, permanent deformation hardly occurs.

Abstract: A dental material of a metal composition for reinforcing the metal framework of a dental restoration comprising an aggregate combination of metal particles including a first high fusing temperature precious metal component and a second low fusing temperature component which form a porous sponge-like structure upon heat treatment.