Abstract: The disclosure relates to a binder, and the method of formulating the said binder, which is suitable for shaping parts from metallic and/or ceramic particles by injection molding. The binder comprises materials that are mainly thermoplastics, each of which having a percentage that is determined by its thermogravimetric analysis (TGA) profile and a weight loss versus highest binder removal rate from a green body by progressive heating. The removal of this binder from the green body is performed within a much shorter period of time than those published in the prior art. An example binder comprises 40-70% HDPE, 18-30% Paraffin wax, 10-25% microcrystalline wax and 2-5% stearic acid. Another binder comprises 35-65% PP, 23-35% paraffin wax, 10-25% microcrystaline wax and 2-5% stearic acid.

Abstract: A sodium-azide-free gas-generating composition includes an oxidizable borohydride fuel and an oxidizing agent containing oxygen and a metal. The fuel and the oxidizing agent are selected such that water vapor is produced upon reaction between the borohydride fuel and the oxidizing agent. Suitable oxidizing agents contain a metal and oxygen and are selected from a metal oxide, a metal oxide hydrate, a metal oxide hydroxide, a metal hydrous oxide, a metal hydroxide, or mixtures thereof. The fuel and oxidizing agent are selected such that water vapor is the major gaseous combustion product.

Abstract: This invention relates to water-in-oil emulsion explosives in which an oxidizing material is contained in the discontinuous water phase, and the continuous oil phase acts as a carbonaceous fuel. More particularly, this invention relates to such explosives in which polyfunctional carboxylic acids, sulfonic acids, or phosphorous-containing acids, soluble in the oil phase, are caused to cross-link using an inorganic cross-linker, thereby causing the viscosity of the emulsion to increase.

Abstract: A sintered electrode having fine pores and coarse pores and intended for use in a voltaic cell is made from reduced iron powder granules, which have been made from an iron(III) oxide powder having a particle size up to 10 micrometers and have a particle size not in excess of 500 micrometers and are compacted to form an electrode body, which is sintered under a reducing atmosphere at a sintering temperature up to 750.degree. C. The iron powder granules are derived from the agglomerated iron powder that is formed as the iron powder is reduced at 600.degree. to 800.degree. C. and optionally after the agglomerated iron powder has been reduced in size, and the iron powder granules before being compacted are mixed with an organic solid expanding agent, which volatilizes during the sintering process and is used in such a proportion and has such a particle size that the resulting sintered electrode has coarse pores in the desired number and the desired size.

Abstract: An improved method of gassing and controlling the density of emulsion explosive compositions is provided. The emulsion explosive compositions of interest include an oxidizer salt, carbonaceous fuel, and an emulsifier. In addition, a catalyst, such as a salt or oxide of iron, copper, or manganese may be added to the explosive composition as a catalyst. The explosive composition is gassed by adding thereto a quantity of a second emulsion which includes an aqueous solution of hydrogen peroxide, a carbonaceous fuel, and an emulsifier. Oxygen gas bubbles are produced throughout the explosive composition by the degradation of the hydrogen peroxide, which may be catalyzed by the metal salt catalyst. The invention provides more uniform gas bubble distribution within the emulsion explosive composition.

Abstract: An explosive composition for mining operations has been produced using waste oil, lignite and ammonium nitrate in selected ranges of concentrations.

Abstract: The invention relates to a method for the continuous reduction and soft annealing of water atomized iron powder which is conducted in the form of a loose powder layer through an indirectly heated treatment chamber with a heating zone, a reduction zone, and a cooling zone. For increasing the throughput while reducing the energy and reduction agent required, it is proposed that the powder layer is revolved during the travel through the treatment chamber with continuous mixing at least in the reduction zone, wherein the temperature is 800.degree.-950.degree. C. and that, for-controlling the dewpoint of the furnace atmosphere, fresh reduction gas is permanently introduced directly into the reduction zone.

Abstract: A process for the production of explosives grade ammonium nitrate prill (EGAN) comprises the steps of(A). producing seed ammonium nitrate prill as substantially monosized prills; and then(B). fattening using melt/solution of ammonium or mixed nitrates, with drying and thermal treatments, the seed prill in an inclined rotating jacketed pan granulator or a cascade of such pans to produce a final fattened EGAN prill product preferably having at most about 4 mm diameter.

Abstract: A multiple beam laser sintering device includes a sintering beam 64 having a focal point at a powder bed 68 and at least one defocussed laser beam 116 incident on a region near the focal point of the focussed beam 64. The sintering beam 64 raises the temperature of the powder 84 to the sintering temperature. The defocussed beam 116 raises the temperature of the material surrounding the sintering beam 64 to a level below the sintering temperature, thereby reducing the temperature gradient between the sintering location and the surrounding material. Thermal radiation may be measured from one or both beams and used to control the power of one or both beams and the power of one or both beams may be controlled to maintain the temperature at a desired level. Alternatively, a plurality of defocussed beams may be used to provide either a plurality of thermal gradient steps, or to control the temperature of each region around the sintering point independently.

Abstract: A process for producing a sintered body, comprising inserting a separately formed first molded article in a mold for injection molding, injection-molding a material identical to or different from that of the first molded article in the mold so that the injected material and the first molded article form together a second molded article, degreasing the second molded article, sintering the degreased article thereby obtaining a sintered body having a difference in shrinkage during the sintering between the first molded article and the injection molded portion of the second molded article other than the first molded article portion being 5% or less. The resulting sintered body is useful as a magnet base.

Abstract: The compound 2,4-dinitroimidazole is highly insensitive towards impact and its thermal stability is excellent. The calculated detonation properties results indicate that its performance is about 30% better than TATB. It can be prepared easily with good yield starting from inexpensive starting materials. Results from impact sensitivity, friction sensitivity time-to-explosion temperature and vacuum stability tests indicate that 2,4-dinitroimidazole is less sensitive than both RDX and HMX. Its good oxygen balance and measured heat of formation data of this material indicate that its propellant performance is good.

Abstract: The process for recovering boron values and fluorine values from an acidic aqueous feed liquor containing substantial fluoroborate moieties, including contacting the feed liquor with basic material to adjust the pH thereof to above about 7.0 and provide a first clarified liquor containing the fluoroborate moieties, and contacting the first clarified liquor at elevated temperature with sufficient cation reactant selected from Al(OH).sub.3 or Al.sub.2 (SO.sub.4).sub.3 to precipitate substantially all of the fluorine values as an aluminum fluoride compound and provide a second clarified liquor containing the boron values as boric acid.

Abstract: The improved binder system for use in the injection molding of sinterable powders such as metal powders, ceramic powders and cermet powders comprises a (co)polymer that has a molecular weight in excess of 2000 and which contains at least one epoxy group in the molecule. Preferably, the binder system comprises said (co)polymer, a (co)polymer other than said (co)polymer, and an organic compound having a molecular weight up to 2000. Using a binder system comprising (a) 3-80 wt % of a (co)polymer that has a molecular weight in excess of 2000 and which has at least one epoxy group in the molecule, (b) up to 70 wt % of a (co)polymer other than component (a), and (c) 20-80 wt % of an organic compound having a molecular weight of not more than 2000, there is provided a composition for the injection molding of sinterable powders. The compound has excellent moldability and strength properties.

Abstract: Metal particulates and porous metal media, which have enhanced resistance to undesirable oxidation, and methods of producing the same are provided. The porous metal media comprise sintered metal particulates each typically having a core and a surface and a diameter in the range of 0.25 to 50 micrometers, the particulates comprising at least about 60 wt. % of a base metal including at least one of iron and nickel, at least about 11 wt. % chromium and no more than about 0.03 wt. % carbon. The surfaces of the particulates are enriched with at least one treatment element in an amount and depth sufficient to enhance the resistance of the particulates to undesirable oxidation. The invention also includes a fine metal filter medium formed from sintered metal fibers, which has enhanced resistance to corrosion and/or to high temperature oxidation.

Abstract: There is disclosed a precious metal article which is formed of a solid-phase sintered product of a precious metal powder. For manufacturing the precious metal article, a moldable mixture which contains a precious metal powder and a binder removable by sintering is shaped into a prescribed molded object, and the molded object is then subjected to sintering. The moldable mixture is produced by preparing a precious metal powder, preparing a jellylike cellulose binder by blending a cellulose with water and leaving for a prescribed period of time, and blending the precious metal powder and the jellylike cellulose binder together. The most preferable moldable mixture contains 50 to 90% by weight of precious metal powder, 0.8 to 8% by weight of water-soluble cellulose binder, 0.08 to 3% by weight of a surface-active agent. 0.1 to 3% by weight of oil, balance water and unavoidable impurities.

Abstract: A density element (12) for use in ruminal delivery devices (10) which is manufactured by partial sintering in such a manner as to fragment upon contact with the many parts in rendering machinery without damage to the blades. The density element (12) has density of at least about 1.5 gm/cm.sup.3 and a transverse rupture strength greater than about 3000 psi no greater than about 30,000 psi. The part is sintered under conditions which do not permit full weld bond strength to be obtained and may thereafter be heat treated or impregnated with an inert hydrophobic material to increase corrosion resistance.

Abstract: Metal carbides may be formed by mixing metal powder with a stoichiometric amount of graphite, compressing the same in a mould/die and then sintering. High temperatures (and maybe a bonding agent) are required to effect the final step and finished product. These disadvantages are overcome by exploiting dry high energy milling to bring the starting materials into a very finely divided and reactive state, with regions of metal, carbon and metal based solid solution ranging from 3 to 100 nanometers in diameter. As an alternative source of carbon, cationic organic surfactants may be used instead of graphite in the appropriate proportion. Compacting the milled mixture, followed by sintering at lower temperatures by a margin of at least 400.degree. C., will produce very strong dense carbides at low cost. The method may be extended to include metal based composites, which also includes cermets, by incorporating an appropriate excess of metal powder(s) in the starting materials.

Abstract: Rocket exit cones, rocket motors, curved objects, and the like, are produced by weaving a fabric onto a non linear form and rotating the form to wind up the fabric as it is being woven. Compensation between the linear, flat shape of the fabric and a non linear shape of the wind up form is obtained by conforming the shape of the reed portion of the loom to the shape of the form, and by providing a constant and/or variable spacing between the reed elements. A uniformly wrapped, non linear shape is is produced by the process.Following wrapping, the fabric shape is impregnated with resin, and cured to a carbonized and/or graphitized state. Finally, the cured shape may be machined to its desired size and contour, having uniform properties.

Abstract: A process for producing YBCO powders by pyrolysis involves preparing a clear aqueous solution containing the ions yttrium, barium and copper, in the final proportions desired for the powder, in the form of complex compounds, preferably citric complex compounds, and in the presence of a detonating system such as a combination of ammonium ions and nitrate ions. The clear solution is then concentrated by evaporation, until a violent combustion is triggered which is carried out at a high temperature, higher than 250.degree. C. and preferably higher than 850.degree. C.

Abstract: A method for producing an article including a refractory compound by infiltrating a preform with a liquid infiltrant and initiating a reaction between the preform and the liquid infiltrant to establish a reaction front which propagates in a direction opposite to the direction of flow of the liquid infiltrant is provided, as are articles prepared according to this method.