Abstract: The coating the tungsten powder particles with a ceramic barrier suppresses the leachability of tungsten in aqueous media. Preferably, the ceramic coating substantially encapsulates each particle of tungsten and has a thickness of at least about 30 nm and, more preferable, from about 200 nm to about 500 nm. Examples of ceramic coatings that may be used include, but are not limited to, aluminum oxide (alumina), aluminum oxyhydroxide (AlOOH), zirconium oxide (zirconia), cerium oxide (ceria), hafnium oxide (hafnia), and magnesium oxide (magnesia).

Abstract: A large-diameter tungsten-lanthana rod having an elongated grain structure substantially parallel to the longitudinal axis of the rod is described. The large diameter rod is produced by rolling at a temperature greater than 1400° C. and less than 1700° C. to achieve at least about a 40% reduction in cross-sectional area. The high strength of the longitudinally elongated grain structure is desirable for applications such as rocket nozzles.

Abstract: A large-diameter tungsten-lanthana rod having an elongated grain structure substantially parallel to the longitudinal axis of the rod is described. The large diameter rod is produced by rolling at a temperature greater than 1400° C. and less than 1700° C. to achieve at least about a 40% reduction in cross-sectional area. The high strength of the longitudinally elongated grain structure is desirable for applications such as rocket nozzles.

Abstract: A large-diameter tungsten-lanthana rod having an elongated grain structure substantially parallel to the longitudinal axis of the rod is described. The large diameter rod is produced by rolling at a temperature greater than 1400° C. and less than 1700° C. to achieve at least about a 40% reduction in cross-sectional area. The high strength of the longitudinally elongated grain structure is desirable for applications such as rocket nozzles.

Abstract: A method of making a composite orifice having a tungsten core which is diffusion bonded to a molybdenum shell. Tungsten and molybdenum powders in contact with each other in a mold are isostatically pressed to form a pressed bonded composite part. The pressed, unsintered tungsten core portion of the part is then machined to the desired dimensions. The pressed composite part is then sintered to form a diffusion bonded composite orifice. The pressed and sintered molybdenum shell portion of the orifice may then be machined to the desired dimensions.

Abstract: A cutting tool for simultaneously forming a plurality of deep, narrow, closely spaced parallel grooves in a hard, brittle substrate material comprises a rigid housing which defines a plurality of closely spaced cutting blade cavities, each of said cavities being constructed to receive and rigidly hold a cutting blade therein, and cutting blades rigidly mounted in each of said cavities.

Abstract: A method of making a threaded tungsten metal part having a diameter or thickness greater than two inches. Tungsten metal powder is hot isostatically pressed and sintered and then machined to the desired thread configuration using a single point tungsten carbide cutting tool.

Abstract: A method is disclosed for deforming a molybdenum based metal part, which involves press forging a powder metallurgically produced part made of material selected from the group consisting of molybdenum metal and molybdenum metal alloys, at a temperature of from about 1700.degree. F. to about 2300.degree. F. at an average strain rate of from about 5 inches per minute to about 20 inches per minute.

Abstract: A method is disclosed for deforming a molybdenum based metal part, which involves press forging a part made of material selected from the group consisting of molybdenum metal and molybdenum metal alloys, at a temperature of from about 1700.degree. F. to about 2300.degree. F. at an average strain rate of from about 5 inches per minute to about 20 inches per minute.

Abstract: A method is disclosed for bonding liquid phase sintered metal powder parts of a tungsten alloy containing nickel. The method involves placing a sheet of copper based material between the parts at their adjoining surfaces to join the parts with the sheet covering essentially the entire area of the surfaces, heating the resulting assembly at a temperature sufficient to melt the copper based material without melting the parts, cooling the resulting heated assembly to room temperature, reheating the assembly at a temperature which is high enough to cause diffusion of the copper based material and the matrix alloying elements into one another without melting the parts, and cooling the resulting twice heated assembly.

Abstract: A method and apparatus are disclosed for producing a powder metal part having a plurality of cavities. The method involves introducing a metal powder and an apparatus into a mold, the apparatus being made of a plurality of solid pieces which are in the shape of the cavities to be formed. The pieces are joined together by joining means and are positioned relative to each other by adjusting means so that the cavities formed therefrom are equally spaced about the center of the part. The apparatus is then removed from the mold, and the powder is then isostatically pressed in the mold to produce a green part which is then sintered to form the final part having the cavities.

Abstract: An improvement is disclosed in a method for producing a metal article of high density comprising pressing a metal powder at a sufficient pressure to form a green article and sintering said green article at a sufficient temperature for a sufficient time to form a sintered article, the improvement being pressing the sintered article at a sufficient temperature for a sufficient time at a sufficient pressure of a non-oxidizing atmosphere to produce the final high density article.