Abstract: A method for the separation of a dispersion of molten aluminium and solid inclusions formed from a melt of aluminium containing one or more foreign chemical elements. Molten aluminium surrounding the solid inclusions is at least essentially replaced by a molten salt.

Abstract: An apparatus is provided for the treatment of molten metal, e.g. aluminum, with a particulate treatment agent and a gas. This includes a vessel for holding molten metal, a rotary device for breaking up particulate treatment agent and gas within the molten metal and for dispersing particulate treatment agent and gas within the molten metal contained in the vessel and means for supplying the particulate treatment agent and gas to the rotary device. The rotary device includes a hollow shaft having a rotor with an axial opening fixed to the discharge end of the shaft, this rotor being in the form of an annular plate with a plurality of radially mounted upwardly directed blades projecting from the top face of the annular plate and a plurality of radially mounted downwardly directed blades projecting from the bottom face of the annular plate.

Abstract: A process is described for treating molten metal with a particulate treating agent. A melt of a metal, e.g. aluminum, is provided in a treatment vessel such as a ladle and a mixing impeller is positioned substantially below the surface of the molten metal. The impeller comprises a plate with a series of spaced blades extending from the surface of the plate. This impeller is adapted to provide high shear mixing with minimum vortex. While rotating the impeller on a substantially vertical axis, particulate treating agent is fed by way of an injection tube below the surface of the molten metal and into the region between the axis and periphery of the impeller. This causes a high shearing action in the region of the blades whereby the treating agent is quickly broken down into finely divided droplets that are at least partially molten and which are circulated within the molten metal.

Abstract: A process is described for treating molten metal with a particulate treating agent. A melt of a metal, e.g. aluminum, is provided in a treatment vessel such as a ladle and a mixing impeller is positioned substantially below the surface of the molten metal. The impeller comprises a plate with a series of spaced blades extending from the surface of the plate. This impeller is adapted to provide high shear mixing with minimum vortex. While rotating the impeller on a substantially vertical axis, particulate treating agent is fed by way of an injection tube below the surface of the molten metal and into the region between the axis and periphery of the impeller. This causes a high shearing action in the region of the blades whereby the treating agent is quickly broken down into finely divided droplets that are at least partially molten and which are circulated within the molten metal.

Abstract: An apparatus is provided for the treatment of molten metal, e.g. aluminum, with a particulate treatment agent and a gas. This includes a vessel for holding molten metal, a rotary device for breaking up particulate treatment agent and gas within the molten metal and for dispersing particulate treatment agent and gas within the molten metal contained in the vessel and means for supplying the particulate treatment agent and gas to the rotary device. The rotary device includes a hollow shaft having a rotor with an axial opening fixed to the discharge end of the shaft, this rotor being in the form of an annular plate with a plurality of radially mounted upwardly directed blades projecting from the top face of the annular plate and a plurality of radially mounted downwardly directed blades projecting from the bottom face of the annular plate.

Abstract: A method of preparing a metal alloy comprising a dispersion of particles of a first metallic material consisting of one or more refractory hard metals in a matrix of a second metallic material includes establishing a molten body of the second metallic material and introducing solid particles of the first metallic material into the molten body. Alternatively solid particles of a metalloid which reacts with the second metallic material to form particles of the first metallic material may be introduced into the molten body. The first metallic material has a higher melting point than the second metallic material and is substantially insoluble therein. The molten body is then stirred at a rate sufficient to effect shearing of the surfaces of the particles such that the surfaces are wetted by the molten body, and the molten body containing the resultant dispersion is cast in any desired manner.

Abstract: Improved apparatus and method are described for the removal of light metals; sodium, lithium, calcium and magnesium, from virgin aluminum tapped from a Hall Heroult reduction cell using LiF-modified or LiF+MgF2 electrolyte. The method is performed in a crucible or at a station intermediate between the cells and furnaces in a cast house. Fine particulate aluminum fluoride and/or sodium aluminum tetrafluoride are transported by a gas or gas mixture into the molten aluminum in a manner such that the light metals are preferentially removed or their concentration substantially lowered through: a) the axle of a specially designed spinning impeller; b) partially through the axle of a specially designed spinning impeller and partially through one or more pipes equipped with dispersers for dispersing into the molten metal flow close to the spinning impeller; or c) through one or more pipes equipped with dispersers for dispersing into the molten metal flow close to the impeller fastened to a solid axle.

Abstract: An improved method of eliminating phosphorus and/or antimony from molten aluminum containing phosphorus and/or antimony is provided, including the step of adding magnesium or calcium to the molten aluminum maintained at a temperature of 650° to 850° C. while blowing chlorine gas or a chloride thereinto, to remove the phosphorus and/or the antimony contained in the molten aluminum.

Abstract: A method of heating a body of molten metal passing through a treatment bay. The method comprises providing a body of molten metal in a treatment bay and providing a baffle heater in the treatment bay to contact the molten metal. The baffle heater is comprised of a member fabricated from a material substantially inert to the molten metal, the member containing at least one heating element receptacle. An electric heating element is positioned in the receptacle for heating the member, the element protected from the molten metal by the material constituting the member.

Abstract: Very fine TiC whiskers having a mean diameter smaller than 1 micron are generated by pellets including Ti powder and graphite powder being added to a molten mass of pure Al or an Al alloy, or by a graphite powder being added to a molten mass of an Al alloy containing Ti, with argon gas being blown into the molten mass so as thereby to generate TiC whiskers in void spaces formed in the molten mass by bubbles of the gas. When the molten mass with the TiC whiskers thus formed therein is compressed, the interstices of the TiC whiskers generated in the void spaces are filled with the molten metal so as thereby to form colonial composite material portions dispersed in the molten mass, thus providing a metallic composite material reinforced by very fine TiC whiskers. The density of the colonial composite material portions can be increased by applying a filtering process to the molten mass.

Abstract: A process for making metal-matrix composite includes adding ultrafine reinforcing material having a particle size as fine as 0.05 .mu.m into the metal alloy matrix in a refining furnace to be homogeneously dispersed in the matrix for producing metal-matrix composite by a refining process, which is degassed to remove gases to eliminate porosity in the composite, thereby producing metal-matrix composite having improved mechanical properties.

Abstract: A method for the production of master alloys intended for grain refining of aluminum melts and being of the type which comprises of aluminum and 1-15 percent by weight titanium, where titanium is present in the form of intermetallic crystals of titanium aluminide in combination with additives of carbon and/or nitrogen. The method is characterized by adding carbon and/or nitrogen to the aluminum melt in an amount corresponding to at least 0.01 percent by weight in the resultant solidified material. The addition of the carbon and/or nitrogen is effected in elemental form or in the form of dissociable carbon and/or nitrogen containing compounds, making said addition before of during an established thermodynamic state of dissolution of existing crystals of titanium aluminide, and bringing the melt into a thermodynamic state where crystals of titanium aluminide present grow in size and thereafter causing the melt to solidify. Also a master alloy produced according to the above method is claimed.

Abstract: A process is described for removing all reinforcing particles contained in metal matrix composite scrap materials. This new technique involves providing a treatment vessel for holding a melt of an aluminum matrix composite to be recycled. Heating means are provided for heating the contents of the vessel to a temperature in the range of 700.degree.-750.degree. C. Mixing of the melt is carried out by means of a power driven vaned rotary impeller and this impeller is operated under different conditions for different stages of the process. In the first mixing stage, the impeller is operated under vortex-forming conditions and a fluxing salt is added to the melt while a gas is injected through a gas outlet beneath the surface of the melt and near the rotating impeller. This causes the salt to rapidly mix with the melt and the inlet gas, providing a uniform distribution through the melt of gas bubbles each surrounded by a layer of liquid salt.

Abstract: A net shaped ceramic-reinforced aluminum matrix composite is produced by forming a permeable mass of ceramic material with a defined surface boundary having a barrier, and contacting a molten aluminum-magnesium alloy with the permeable mass of ceramic material in the presence of a gas comprising from about 10 to 100% nitrogen, by volume, balance nonoxidizing gas, e.g. hydrogen or argon. Under these conditions, the molten alloy spontaneously infiltrates the ceramic mass under normal atmospheric pressures until it reaches the barrier. A solid body of the alloy can be placed adjacent to a permeable bedding of ceramic material having a barrier, and brought to the molten state, preferably to at least about 700.degree. C., in order to form the net shape aluminum matrix composite by spontaneous infiltration. In addition to magnesium, auxiliary alloying elements may be employed with aluminum. The resulting composite products may contain a discontinuous aluminum nitride phase in the aluminum matrix.

Abstract: A lance and method for injecting particulate matter into molten metal is disclosed. The lance includes an injector conduit for introducing particulate matter into a molten metal. A heat removal site surrounds at least a portion of the injector conduit. An insulating sleeve surrounds at least a portion of the heat removal site to minimize heat transfer from molten metal. The lance is placed in molten metal and a coolant gas is circulated through the heat removal site while particulate matter is injected into the molten metal.