Abstract: A method is disclosed for producing silicon nitride wherein the crystal morphology is controlled. The method involves heating a mixture consisting essentially of a chlorosilane and ammonia at a sufficient temperature for a sufficient time to produce a nitogen containing silane as an intermediate. The bulk density of the intermediate is controlled to less than about 0.1 g/cc to result in the silicon nitride having a crystal morphology which is essentially all fibrous, or the bulk density can be controlled to greater than about 0.3 g/cc to result in the silicon nitride having a crystal morphology which is essentially all equiaxial, or the bulk density can be controlled to between about 0.1 g/cc and about 0.3 g/cc to result in the silicon nitride having a crystal morphology which is a mixture of fibrous and equiaxial. The intermediate is then heated at a sufficient temperature for a sufficient time in a non-oxidizing atmosphere to produce the controlled crystal morphology silicon nitride.

Abstract: A low density tungsten alloy article is disclosed and the method for producing the article. The method involves compacting a relatively uniform tungsten alloy powder with the tungsten content comprising no greater than about 90% by weight of the alloy and the balance a matrix phase to produce a preformed article which is then sintered in a reducing atmosphere at a temperature below the melting point of the matrix phase for a sufficient time to form a densified article which is mechanically worked to produce the final article.

Abstract: A powdered material and a process for producing the material are disclosed. The powdered material consists essentially of titanium based spherical particles which are essentially free of elliptical shaped material and elongated particles having rounded ends. The material has a particle size of less than about 50 micrometers. The process for making the spherical particles involves mechanically reducing the size of a starting material to produce a finer powder which is then entrained in a carrier gas and passed through a high temperature zone above the melting point of the finer powder to melt at least about 50% by weight of the powder and form spherical particles of the melted portion. The powder is then directly solidified.

Abstract: A powder material and a process for producing the material are disclosed. The powder material consists essentially of iron group based and chromium based spherical particles. The material is essentially free of elliptical shaped material and elongated particles having rounded ends. The material has a particle size of less than about 20 micrometers in diameter and has an oxygen content of less than about 0.8% by weight. The process for making the spherical particles involves reducing the size of a starting material to produce a finer powder essentially all of which has a particle size of less than about 20 micrometers in diameter. This is done by fluid energy milling. The finer powder is entrained in a carrier gas and passed through a high temperature zone at a temperature above the melting point of the powder, the temperature being from about 5500.degree. C. to about 17,000.degree. C.

Abstract: A powdered material and a process for producing the material are disclosed. The powdered material consists essentially of refractory metal based spherical particles and is essentially free of elliptical shaped material and elongated particles having rounded ends. The process for making the spherical particles involves mechanically reducing the size of a starting material to produce a finer powder which is then entrained in a carrier gas and passed through a high temperature zone at a temperature above the melting point of the finer powder to melt at least about 50% by weight of the powder and form the spherical particles of the melted portion. The powder is then directly solidified.

Abstract: A powder material and a process for producing the material are disclosed. The powder material consists essentially of spherical particles selected from the group consisting of metals, metal alloys, ceramic glasses, crystalline ceramic materials, and combinations thereof. The material is essentially free of elliptical shaped material and elongated particles having rounded ends. The material has a particle size of less than about 20 micrometers in diameter and has an oxygen content of less than about 0.8% by weight. The process for making the spherical particles involves reducing the size of a starting material to produce a finer powder essentially all of which has a particle size of less than about 20 micrometers in diameter. This is done by fluid energy milling. The finer powder is entrained in a carrier gas and passed through a high temperature zone at a temperature above the melting point of the powder, the temperature being from about 5500.degree. C. to about 17,000.degree. C.

Abstract: A method is disclosed for producing a high hardness refractory metal part, the method comprising hot isostatic pressing a refractory metal part having a density greater than about 98% of the theoretical density in the presence of a pressurizing gas having an atomic size great enough to strain the lattice of the refractory metal at a pressure to exceed the yield strength of the metal to result in the densification of the part to a density of greater than about 98% of the theoretical density. The part is then rapidly cooled. The resulting part has a hardness approaching the hardness of mechanically worked material.

Abstract: A process is disclosed for producing fine spherical powder particles. The process involves forming a relatively uniform admixture of a starting powder material and a flowability aid, the flowability aid being non-reactive with and coarser than the starting material, entraining the admixture in a carrier gas and passing the admixture through a high temperature zone at a temperature above the melting point of the starting material to melt at least about 50% by weight of the starting material, resolidifying the resulting high temperature treated material, and separating the flowability aid from the balance of the high temperature treated material.

Abstract: A powdered material and a process for producing the material are disclosed. The powdered material consists essentially of light metal based spherical particles which are essentially free of elliptical shaped material and elongated particles having rounded ends. The process for making the spherical particles involves mechanically reducing the size of a starting material to produce a finer powder which is then entrained in a carrier gas and passed through a high temperature zone above the melting point of the finer powder to melt at least about 50% by weight of the powder and form spherical particles of the melted portion. The powder is directly solidified.

Abstract: A powdered material and a process for producing the material are disclosed. The powdered material consists essentially of iron group based and chromium based spherical particles. The material is essentially free of elliptical shaped material and elongated particles having rounded ends. The material has a particle size of less than about 20 micrometers. The process for making the spherical particles involves mechanically reducing the size of a starting material to produce a finer powder the major portion of which has a particle size of less than about 20 micrometers. The finer powder is entrained in a carrier gas and passed through a high temperature zone at a temperature above the melting point of the powder to melt at least about 50% by weight of the powder and form the spherical particles of the melted portion. The powder is then directly solidified.

Abstract: A process is disclosed for producing a sheet of tungsten heavy alloy which involves uniformly blending metal powder compnents of the alloy by forming a slurry of the powder components and one or more chemical compounds of at least one of the components of the alloy as an inorganic binder in a liquid medium, the chemical compound being soluble in the liquid medium and capable of being decoposed into one or more of the metal components of the alloy below the melting point of the metal powder components, removing the liquid medium from the powder components and forming a planar cake of the powder components and said inorganic binder, drying the cake, heating the cake to a temperature sufficient to decompose the inroganic binders into their elemental components or oxides, followed by heating the cake in a reducing atmosphere at a temperature sufficient to reduce any oxides forming during the previous steps to the metals, and sintering the cake to a density equal to or greater than about 90% of the theoretical den

Abstract: A process is disclosed for producing a tungsten heavy alloy sheet which involves rolling a starting slab consisting essentially of tungsten heavy alloy wherein the tungsten content is from greater than 75% to 93% by weight tungsten by passing the slab one or more times through a rolling mill at a temperature of from 700.degree. C. to 900.degree. C. to reduce the height of the slab by no greater than 10% per pass to a total reduction in height of from 15% to 25%, heating the resulting slab from the first series at a temperature of 1000.degree. C. to 1200.degree. C. for a sufficient time to anneal the matrix of the slab, subjecting the resulting first time annealed slab to a second series of rolling operations by passing the first time annealed slab one or more times through a rolling mill at a temperature of 700.degree. C. to 900.degree. C.

Abstract: A method is disclosed for shaping parts made of tungsten and of tungsten with thoria. The method involves machining the parts with a machining apparatus wherein the machining tool is made of diamond or material of which tungsten carbide is the main phase, the material having a hardness of greater than about 91 Rockwell A, the machining being done at a speed of from about 40 to about 120 surface feed per minute, and a feed rate of from about 0.0002 to about 0.006 inches per revolution. Machining of parts made of tungsten is done with cooling with a halocarbon solvent. Machining of parts made of tungsten and thoria can be done with or without cooling.

Abstract: A process is disclosed for producing tungsten heavy alloy sheet. The process comprises crystallizing from solution the compounds of the component metals of the alloy, and drying the compounds, introducing the compounds into a container so that the compounds are loosely and uniformly packed in the container, the container being made of molybdenum coated with a ceramic, and having the same shape as the sheet which is to be made. The compounds are then reduced to their respective metals and the resulting metal powder is sintered to a density equal to or greater than about 90% of the theoretical density of the alloy to form the sheet.

Abstract: A process is disclosed for producing a sheet of tungsten heavy alloy which comprises forming a solution of chemical compounds containing the metal values of the alloy in the correct proportion as in the alloy, forming from the solution a precipitate of the compounds containing the metal values, removing the precipitate from the resulting liquor an forming a planar cake of the precipitate, drying the cake, and reducing the compounds in the cake to their respective metals wherein each of the resulting reduced particles is an admixture of the alloy components and sintering the cake to a density equal to or greater than about 90% of the theoretical density of the alloy to form the sheet.

Abstract: A method is disclosed for removing essentially all of the water from fine metal powders. The method involves contacting the powder particles which have water on at least some of the particle surfaces with a solution of a fluorocarbon solvent and a hydrophobic surfactant, with the amount of the surfactant being sufficient to form at least a monolayer adsorbed onto the particle surfaces, and with the amount of the solution being sufficient to at least fill the void volume of the particles, to displace essentially all of the water which is in contact with the water. The displaced water and the major portion of the solution which is not in direct contact with the powder is physically removed from the resulting treated powder. The powder is then dried at a temperature above the vaporization temperature of the fluorocarbon at the operating pressure of the drying equipment to remove the remainder of the fluorocarbon from the treated powder without removing significant amounts of surfactant therefrom.

Abstract: A disc is disclosed which comprises a top layer, a middle layer, and a bottom layer. The top layer is placed proximate to a high temperature reactor and at least the outer surface of the top layer is made of a material which allows it to act as a substrate against which molten particles are impacted to microatomize the particles. The layers are positioned one above the other with a first space between the bottom surface of the top layer and the top surface of the middle layer, and a second space between the bottom surface of the middle layer and the top surface of the bottom layer. The top and bottom layers are joined together and stabilized by a peripheral wall around the circumferential edge of the top and bottom layer. The middle layer is fixedly mounted to the bottom layer. The middle layer is smaller in diameter than the diameters of the top and bottom layers so that a third space is defined between the inner surface of the peripheral wall and the circumferential edge of the middle layer.

Abstract: An improvement is disclosed in a process wherein tungsten values are extracted from an aqueous alkali metal tungstate solution by an organic extractant, and then stripped from the organic with an ammonia solution, the improvement being removing bromine from the major portion of the stripped organic and thereafter using at least a portion of the resulting bromine-free stripped organic to make up at least a portion of the organic extractant.

Abstract: A powdered material and a process for producing the material are disclosed. The powdered material consists essentially of spherical particles selected from the group consisting of metals, metal alloys, ceramic glasses, crystalline ceramic materials, and combinations of these. The material is essentially free of elliptical shaped material and elongated particles having rounded ends. The material has a particle size of less than about 20 micrometers. The process for making the spherical particles involves mechanically reducing the size of a starting material to produce a finer powder the major portion of which has a particle size of less than about 20 micrometers. The finer powder is entrained in a carrier gas and passed through a high temperature zone at a temperature above the melting point of the powder to melt at least about 50% of the powder and form the spherical particles of the melted portion. The powder is then directly solidifed.

Abstract: A process is disclosed for producing discontinuous metal foils. The process involves entraining metal powder particles in a carrier gas and passing the powder particles through a high temperature zone at a temperature above the melting point of the powder particles to melt at least about 50% by weight of the powder particles and thereafter resolidifying the resulting high temperature treated material by impacting the material against a substrate to form the foils.