Abstract: A method for separating a certain metal from a raw material including a mixture of the metal and an element which has a lower vapor pressure than the metal. The raw material including the mixture of the metal and the element is heated so as to cause a first vapor including the metal to be evolved. This first vapor is passed through a throttling means in which it undergoes adiabatic expansion and is rapidly cooled so that at least part of it is reduced to a liquid containing the metal. This liquid is reheated so as to cause a second vapor including the metal to be evolved. And the second vapor is cooled to collect the metal. An apparatus is also disclosed for performing this method.

Abstract: A composite material having a high molecular weight polymer material as the matrix material and extremely fine particles of diameters of the order of tens to hundreds of angstroms dispersed in the matrix material is obtained by rapidly adiabatically cooling vapor of a metallic material through a nozzle, and squirting a jet of said fine particles into a molten mass of the high molecular weight polymer material. Optionally, inert gas may be squirted through the nozzle along with the vapor of the metallic material. Further, optionally a gas which forms a compound with the metallic material may be squirted through the nozzle with vapor of the metallic material, so that the particles become particles of a compound of the metallic material and the gas.

Abstract: A composite material having a first metallic material as the matrix material and extremely fine particles of diameters of the order of tens to hundreds of angstroms of a second metal dispersed in this metallic matrix material is obtained by rapidly adiabatically cooling vapor of the second metallic material through a nozzle, and squirting a jet of fine particles produced thereby into a molten mass of the first material. Optionally, inert gas may be squirted through the nozzle along with the vapor of the second metallic material.

Abstract: A ceramic surface-metallic core particle composite fine powder material is disclosed, composed of fine particles each having a metallic core and a ceramic surface layer, in which the average value of the ratio of the thickness of the surface layer of a powder particle to the radius of the particle is subtantially greater than 0.05. A method and an apparatus for making this material from core metal and a gas which combines with the core metal to form the ceramic outer layer are also described, in which a gaseous mixture of vapor of the core metal and the gas is passed through a convergent-divergent nozzle and is thereby rapidly cooled by adiabatic expansion so that the core metal as it solidifies forms metal cores for fine particles while the gas reacts with the outer layers of these particles to form ceramic surface layers.

Abstract: A composite fine powder material is made of first particles with average particle diameter less than or equal to about ten microns, each having a composite structure and being made up of a plurality of fine second particles of a ceramic made by reacting together a first metal and a gas, embedded in a matrix of a second metal. This composite fine powder material is made by vaporizing the first metal, mixing the vapor with the gas, expanding the mixture through a first nozzle mechanism for providing adiabatic expansion cooling under reaction between the first metal and the gas to provide the fine second particles of ceramic, producing vapor of the second metal and mixing it in with the fine second particles at the downstream of the first nozzle mechanism, directing the resulting mixture through a second expansion nozzle mechanism to form the first particles of composite structure, and then collecting these first particles.

Abstract: A magnetic fluid having a base liquid and magnetic particles with so small average particle diameter as to be of some hundreds of angstroms dispersed in the base liquid. Such a magnetic fluid is produced by ejecting a molten magnetic metal adiabatically from an expansion nozzle against a bath of a base liquid.

Abstract: Fine powder of a metal is made by vaporizing the metal in a vaporization chamber, mixing the metallic vapor with an inert carrier gas, and then adiabatically expanding the mixture through a nozzle, which preferably is a convergent-divergent nozzle. A jet flow from the nozzle is very rapidly cooled by this adiabatic expansion, which quickly condenses the metal vapor in the jet flow into very fine particles. Optionally the jet flow is directed against a metal powder collecting means, which may be a collection plate, but preferably is a bath of oil which entrains the particles and keeps them from agglomerating together by partially neutralizing their surface activity. Thus fine metal powder with particle diameters of the order of a few hundreds of angstroms can be economically produced.

Abstract: Fine powder of an alloy of two or more metals is made by vaporizing each of these metals in its own vaporization chamber, mixing each of the metallic vapors with an inert carrier gas, and then adiabatically expanding each of the mixture gases through its own nozzle, which preferably is a convergent-divergent nozzle. Jet flows from the nozzles are collided together, after having been very rapidly cooled by this adiabatic expansion, and thereby the metal vapors in the jet flows are quickly condensed into very fine alloy particles. Optionally the combined flows from the jets are directed against an alloy powder collecting means, which may be a collection plate, but preferably is a bath of oil which entrains the alloy particles and keeps them from agglomerating together by partially neutralizing their surface activity. Thus fine alloy powder with particle diameters of the order of a few hundreds of angstroms can be economically produced.

Abstract: A composite material made of a matrix of a first metal and reinforcing first particles with average particle diameter less than or equal to about ten microns dispersed in the first metal matrix, with the reinforcing first particles each having a composite structure, being made up of a plurality of fine second particles of a ceramic made by reacting together a second metal and a gas and being combined with one another by a matrix of a third metal.

Abstract: A ceramic surface-metallic core particle composite fine powder material is disclosed, composed of fine particles each having a metallic core and a ceramic surface layer, in which the average value of the ratio of the thickness of the surface layer of a powder particle to the radius of the particle is substantially greater than 0.05. A method and an apparatus for making this material from core metal and a gas which combines with the core metal to form the ceramic outer layer are also described, in which a gaseous mixture of vapor of the core metal and the gas is passed through a convergent-divergent nozzle and is thereby rapidly cooled by adiabatic expansion so that the core metal as it solidifies forms metal cores for fine particles while the gas reacts with the outer layers of these particles to form ceramic surface layers.

Abstract: A composite material including matrix metal and ceramic surface - metallic core fine powder material is disclosed, composed of fine particles each having a metallic core and a ceramic surface layer, in which the average value of the ratio of the thickness of the surface layer of a powder particle to the radius of the particle is substantially greater than 0.05, dispersed within a matrix of matrix metal.

Abstract: A method of making a fine powder of a metal and another element in an intimate mutual relation such as an alloy or a chemical compound of a metal and a non metallic element, wherein a gaseous mixture of the metal and the other element is passed through a convergent-divergent nozzle and is thereby rapidly cooled by adiabatic expansion so that the metal and the other element react with each other while the resulting alloy or chemical compound is solidified to form fine particles.