Abstract: Molten magnesium alloy is stirred under a substantially inert atmosphere as it is cooled to freezing, thereby forming discrete solid particles of the alloy. The process may be carried out batch-wise or continuously.
Abstract: A method and apparatus for manufacturing bars made of an alloy by unidirectional solidification.The mold is moved relative to a hot source and a cold source disposed below the hot source. The relative positions of the two sources as well as their efficiency and the displacement speed of the mold are set so that there is established within the alloy contained in the mold a planar solidification front with a high thermal gradient at the level of the front, and so that there is produced an orientation of the structure of the alloy which is perpendicular to the solidification front. During the whole duration of the solidification, the mold is fed with alloy powder having the required nominal composition at the rate corresponding to the quantity of alloy solidified per unit of time.
Type:
Grant
Filed:
September 30, 1981
Date of Patent:
July 10, 1984
Assignee:
Office National d'Etudes et de Recherches Aerospatiales
Inventors:
Jean-Michel Hauser, Fernand Pautonnier, Maurice Rabinovitch
Abstract: An aggregate and/or integrate comprising of silver and tin oxides and/or tin alloy oxides of 4-25 weight % which have been prepared to have the oxides dispersed in the silver, are subjected to a temperature above the melting point of silver, whereby an electrical contact material made from said aggregate and/or integrate comes to have a continuous silver matrix as if produced by an internal oxidation method and also to have such uniform dispersion of the metal oxides in said silver matrix which is comparable or superior to that producible by a powder metallurgical method. The above-mentioned heat treatment is accompanied with hammer or press forging resulting in dimensional reduction of the aggregate and/or integrate such as their shaping, upsetting, and drawing-down. The contact material has, in addition to an excellent elongation and high conductivity, much greater resistance to shock.
Abstract: A process for producing a fiber-reinforced metal composite material which comprises mixing an inorganic fiber with an aluminum alloy at a temperature of not lower than the melting point of said alloy to form a composite,(1) removing the composite from the mold at a temperature of not higher than the solid phase line of said alloy (i.e. a temperature at which a liquid phase appears in said alloy) and heating the composite to a temperature of more than the solid phase line and holding the temperature (heat treatment) during a definite time (Indirect method), or(2) without allowing to cool the composite to a temperature of not higher than the solid phase line (Direct method),quenching the composite to a temperature of 200.degree. C. or lower from a temperature of higher than the solid phase line but lower than the melting temperature.
Abstract: A substantially homogeneous calcium/aluminum alloy having a calcium/aluminum atomic ratio of from about 60/40 to 80/20 and with useful and unexpected properties of brittleness, passivity to atmospheric moisture and low volatility is prepared by a process which comprises adding aluminum under an inert atmosphere to molten calcium at a temperature of from about 550.degree. to 1100.degree. C. and at a rate to prevent substantial solids formation in the melt during the addition. The molten alloy is converted to particulate solid either by melt atomization or by casting, crushing and grinding. Lead/calcium/aluminum and tin/calcium/aluminum alloys are prepared by adding the calcium/aluminum alloy to the molten lead or tin, while calcium/aluminum/lithium alloy is prepared by adding lithium to the molten calcium/aluminum alloy.
Abstract: The problem of CdTe sticking to quartz boats is avoided by preventing any presence of cadmium oxides in the as-compounded CdTe. This is accomplished by distilling the cadmium under a high vacuum immediately prior to the CdTe compounding step.
Abstract: Calcium and aluminum are alloyed into lead by adding a eutectic calcium-aluminum alloy to molten lead preferably at a temperature of at least 1020.degree.. The eutectic alloy contains about 73% calcium and about 27% aluminum.
Abstract: The invention is a method for adding substantially insoluble material to an at least partially liquid metal. The method comprises providing a combination of a first metal having discrete degenerate dendrites and a plurality of insoluble particles at least partially suspended in the first metal. The combination is mixed with a second metal at a temperature above the solidus temperature of the first metal and the second metal. The second metal is capable of forming a dendritic structure when cooled from a liquid state to a solid state. The mixture is then solidified into a dendritic-containing metallic structure having a plurality of substantially insoluble particles at least partilly suspended in the structure.
Abstract: Metal is separated from a gaseous mixture formed during reduction of a compound and which contains metal vapour by contacting the compound with an absorbent capable of absorbing the metal vapour and under thermodynamic conditions such that the metal vapour is directly absorbed by the absorbent.
Abstract: A method of preparing a charge of super alloy material for use in metal casting is disclosed. Thin wall tubes consisting of one of the metallic elements of the alloy material, or an alloy of such element are provided. If an alloy tube is selected, all elements in the tube alloy must also be materials included in the overall formulation of the alloy material. The type and quantity of the materials contained in the tubes is deducted from the quantities set forth in the overall formula and the balance of the formula is melted and poured under vacuum as a core in the tube using the tube as a mold. The resulting master charge is cut into unit charges each of a predetermined weight. These unit charges are then used in a subsequent casting operation by melting the entire unit charge under vacuum to cast precision products of an alloy which consists of the mixed and alloyed materials of both the tube and the core.
Abstract: A mixing device (e.g., a stirrer) to ensure thorough mixing of metals and metal alloys comprising a generally rectangular solid and a series of off-side, but area-equivalent ports on each side of the axial center, wherein the size and number of ports on one side is different from the size and number of ports on the other side, the upper and lower limits of the ports being defined by oppositely opposed anguarly directed fin portions wherein the fins on one side of the axial center are directed in one direction and the fins on the other side of the axial center are directed in the opposite direction. The invention also embodies a method of mixing molten metals and alloys with the device.
Abstract: Master alloys of lithium or other alkali metal with a second metal such as alumium are made by exposing mechanically aloyed powder of the second metal to molten alkali metal. The exposure can be in an inert liquid medium such as a high boiling point hydrocarbon or in a dry, inert gas medium. In order that contact between the lithium and the second metal be efficient, significant, shear inducing agitation is required when the process is carried out in a liquid medium and kneading action, either manual or mechanical is required when the process is carried out dry in an inert gas medium.
Abstract: A process for producing an agglomerated metallurgical composition involving contacting a flowable mass of metal powder, e.g. aluminum powder having a melting point above about 500.degree. C. with a lesser mass of alkali metal, e.g. lithium at a temperature between the melting point of the alkai metal and the melting point of the metal of the powder. The contact is made under a protective atmosphere, e.g. argon or helium and is effected by kneading the metal powder and the molten metal for sufficient time to form agglomerates of substantially uniform composition.
Type:
Grant
Filed:
July 9, 1982
Date of Patent:
June 21, 1983
Assignee:
Novamet, Inc.
Inventors:
Donald L. Erich, Alfred J. Varall, Jr., Stephen J. Donachie
Abstract: A process for combined production of metal alloys, containing zirconium, iron, silicon and aluminium, and of a zirconium corundum, which method comprises melting charge materials, such as a zirconium concentrate, an iron ore and aluminium taken in a weight ratio of 51-69: 9.9-16.5: 19.8-34.8, respectively, at a temperature of 1,950.degree. to 2,000.degree. C., and a separate pouring of end products, the zirconium corundum being poured first. The remaining metal alloy is melted, prior to pouring, with fluxes taken in amounts of 5 to 35% by weight of the zircon concentrate and with charge materials, such as ferrosilicon, taken in an amount of 3 to 102% by weight of silicon of the total weight of the zircon concentrate, ferrosilicon, ferromanganese or metallic manganese taken in an amount of 3 to 26% by weight of manganese of the total weight of the zircon concentrate, at a temperature ranging from 1,950.degree. to 2,000.degree. C.
Type:
Grant
Filed:
February 9, 1981
Date of Patent:
December 14, 1982
Inventors:
Boris A. Shushlebin, Nikolai A. Bogdanov, Viktor V. Tregubenko, Nikolai I. Subbotin, Mikhail V. Galkin