The invention comprises methods and apparatuses for the electrorefining of Mg from Al or Mg alloy scrap. The invention utilizes the density and charge features of Mg present in a melted alloy to continuously extract Mg and Mg alloys from a melted Al alloy feed.

A process for producing an ordered martensitic iron nitride powder that is suitable for use as a permanent magnetic material is provided. The process includes fabricating an iron alloy powder having a desired composition and uniformity; nitriding the iron alloy powder by contacting the material with a nitrogen source in a fluidized bed reactor to produce a nitride iron powder; transforming the nitride iron powder to a disordered martensitic phase; annealing the disordered martensitic phase to an ordered martensitic phase; and separating the ordered martensitic phase from the iron nitride powder to yield an ordered martensitic iron nitride powder.

A CVD-SiC formed body has low light transmittance and high resistivity, and may suitably be used as a member for an etcher that is used for a semiconductor production process, for example. The SiC formed body is formed using a CVD method, and includes 1 to 30 mass ppm of boron atoms, and more than 100 mass ppm and 1000 mass ppm or less of nitrogen atoms. The SiC formed body preferably has a resistivity of more than 10 .Math.cm and 100,000 .Math.cm or less, and a light transmittance at a wavelength of 950 nm of 0 to 1%.

The invention comprises methods and apparatuses for the electrorefining of Mg from Al or Mg alloy scrap. The invention utilizes the density and charge features of Mg present in a melted alloy to continuously extract Mg and Mg alloys from a melted Al alloy feed.

A composition having nanoparticles of a boron carbide and a carbonaceous matrix. The composition is not in the form of a powder. A composition comprising boron and an organic component. The organic component is an organic compound having a char yield of at least 60% by weight or a thermoset made from the organic compound. A method of combining boron and an organic compound having a char yield of at least 60% by weight, and heating to form boron carbide or boron nitride nanoparticles.

A method for producing a silicon nitride substrate includes a raw material powder preparation step of preparing a raw material powder containing a silicon powder, a rare earth element compound, and a magnesium compound, wherein, when the amount of silicon in the raw material powder is expressed in terms of a silicon nitride content, the raw material powder contains the rare earth element compound at 1 mol % to 7 mol % in terms of an oxide content and contains the magnesium compound at 8 mol % to 15 mol % in terms of an oxide content; a sheet forming step of forming the raw material powder into a sheet article; a nitriding step of heating the sheet article in a nitrogen atmosphere at 1200 C. to 1500 C. and nitriding silicon contained in the sheet article; and a sintering step of sintering the sheet article under a nitrogen atmosphere after the nitriding step.

Methods of producing silicon carbide, and other metal carbide materials. The method comprises reacting a carbon material (e.g., fibers, or nanoparticles, such as powder, platelet, foam, nanofiber, nanorod, nanotube, whisker, graphene (e.g., graphite), fullerene, or hydrocarbon) and a metal or metal oxide source material (e.g., in gaseous form) in a reaction chamber at an elevated temperature ranging up to approximately 2400 C. or more, depending on the particular metal or metal oxide, and the desired metal carbide being produced. A partial pressure of oxygen in the reaction chamber is maintained at less than approximately 1.0110.sup.2 Pascal, and overall pressure is maintained at approximately 1 atm.

A thermal protection system (TPS) comprising a mixture of silicon carbide and SiO.sub.x that has been converted from Si that is present in a collection of diatom frustules and at least one diatom has quasi-periodic pore-to-pore separation distance d(p-p) in a selected range. Where a heat shield comprising the converted SiC/SiO.sub.x frustules receives radiation, associated with atmospheric (re)entry, a portion of this radiation is reflected so that radiation loading of the heat shield is reduced.

A method is described for manufacturing a ceramic composite structure. The method includes wrapping ceramic fibers (22), such as SiC fibers, about the external surface of at least one form. The method further includes heating the wrapped fibers (22) to a temperature no greater than a first temperature, infiltrating voids (24) in the wrapped fibers (22) with the ceramic composite in a first vessel (12) at the first temperature, transferring the infiltrated wrapped fibers (22) from the first vessel (12) to a second vessel (14), distinct from the first vessel (12), and coating the infiltrated wrapped fibers (22) with the ceramic composite in the second vessel (14) at a second temperature, higher than the first temperature.

A method of manufacturing an electrically conductive mayenite compound, includes preparing a body to be processed including a mayenite compound; and placing the body to be processed in the presence of carbon monoxide gas and aluminum vapor supplied from an aluminum source without being in contact with the aluminum source and retaining the body to be processed at a temperature range of 1080 C. to 1450 C. under a reducing atmosphere.