Abstract: A decoating system includes a dust cyclone and a dust briquetter. The dust cyclone is configured to receive an exhaust gas from a decoating kiln of the decoating system and remove organic particulate matter from the exhaust gas as dust. The dust briquetter is configured to receive the dust from the dust cyclone and compress the dust into dust briquettes.

Abstract: A method of producing a clad metal ingot suitable for rolling to form a clad metal sheet, and the clad metal ingot so produced. The method involves providing a solid core ingot having an upper side with a rolling face thereon having cavities extending inwardly into the ingot from the rolling face. All or all-but-one of the cavities are blocked against molten metal entry and casting cores extending outwardly from the rolling surface are provided in alignment with the cavities. Molten cladding metal is cast on the rolling face around the casting cores to produce a composite ingot and the casting cores are removed to produce voids in the cladding layer, and the cavities are unblocked. The resulting interconnected cavities and voids are filled with a molten metal to form cast-in-place metal lugs keying or pinning the cladding layer to the core ingot.

Abstract: A metallic alloy having a semi-solid range between the liquidus temperature and the solidus temperature of the metallic alloy is processed by cooling the metallic alloy from an initial metallic alloy elevated temperature to a semi-solid temperature of less than the liquidus temperature and more than the solidus temperature, and maintaining the metallic alloy at the semi-solid temperature for a sufficient time to produce a semi-solid structure in the metallic alloy of a globular solid phase dispersed in a liquid phase. The cooling may be accomplished by providing a crucible at a crucible initial temperature below the solidus temperature, pouring the metallic alloy into the crucible, and allowing the metallic alloy and the crucible to reach a thermal equilibrium between the liquidus temperature and the solidus temperature of the metallic alloy.

Abstract: A method of producing a clad metal ingot suitable for rolling to form a clad metal sheet, and the clad metal ingot so produced. The method involves providing a solid core ingot having an upper side with a rolling face thereon having cavities extending inwardly into the ingot from the rolling face. All or all-but-one of the cavities are blocked against molten metal entry and casting cores extending outwardly from the rolling surface are provided in alignment with the cavities. Molten cladding metal is cast on the rolling face around the casting cores to produce a composite ingot and the casting cores are removed to produce voids in the cladding layer, and the cavities are unblocked. The resulting interconnected cavities and voids are filled with a molten metal to form cast-in-place metal lugs keying or pinning the cladding layer to the core ingot.

Abstract: A cast composite material is prepared by furnishing an aluminum-based matrix alloy and forming a mixture of free-flowing boron carbide particles and the aluminum-based matrix alloy in molten form which is stirred to wet the matrix alloy to the boron carbide particles and to distribute the particles throughout the volume of the melt. The molten mixture is then cast. The fluidity of the molten mixture is maintained by (a) maintaining the magnesium content of the matrix metal below about 0.2% by weight, or (b) starting with a matrix metal containing less than 0.2% by weight magnesium and adding further magnesium to the mixture a short time before casting, or (c) having at least 0.2% by weight titanium present in the mixture.

Abstract: A metallic alloy having a semi-solid range between the liquidus temperature and the solidus temperature of the metallic alloy is processed by cooling the metallic alloy from an initial metallic alloy elevated temperature to a semi-solid temperature of less than the liquidus temperature and more than the solidus temperature, and maintaining the metallic alloy at the semi-solid temperature for a sufficient time to produce a semi-solid structure in the metallic alloy of a globular solid phase dispersed in a liquid phase. The cooling may be accomplished by providing a crucible at a crucible initial temperature below the solidus temperature, pouring the metallic alloy into the crucible, and allowing the metallic alloy and the crucible to reach a thermal equilibrium between the liquidus temperature and the solidus temperature of the metallic alloy.

Abstract: A metallic alloy having a semi-solid range between the liquidus temperature and the solidus temperature of the metallic alloy is processed by cooling the metallic alloy from an initial metallic alloy elevated temperature to a semi-solid temperature of less than the liquidus temperature and more than the solidus temperature, and maintaining the metallic alloy at the semi-solid temperature for a sufficient time to produce a semi-solid structure in the metallic alloy of a globular solid phase dispersed in a liquid phase. The cooling may be accomplished by providing a crucible at a crucible initial temperature below the solidus temperature, pouring the metallic alloy into the crucible, and allowing the metallic alloy and the crucible to reach a thermal equilibrium between the liquidus temperature and the solidus temperature of the metallic alloy.

Abstract: A metallic alloy having a semi-solid range between the liquidus temperature and the solidus temperature of the metallic alloy is processed by cooling the metallic alloy from an initial metallic alloy elevated temperature to a semi-solid temperature of less than the liquidus temperature and more than the solidus temperature, and maintaining the metallic alloy at the semi-solid temperature for a sufficient time to produce a semi-solid structure in the metallic alloy of a globular solid phase dispersed in a liquid phase. The cooling may be accomplished by providing a crucible at a crucible initial temperature below the solidus temperature, pouring the metallic alloy into the crucible, and allowing the metallic alloy and the crucible to reach a thermal equilibrium between the liquidus temperature and the solidus temperature of the metallic alloy.

Abstract: A composite material having less than about 25 volume percent refractory particles in a metal matrix is concentrated to have about 37-45 volume percent refractory particles. The concentrating is accomplished by heating the composite material to melt the matrix, and then contacting the molten composite material to a porous element having an average pore size greater than that of the average particle size. A small pressure differential, on the order of about one atmosphere, is applied across the porous element, so that metal matrix material separates from the composite material and flows through the porous element. The particulate volume fraction in the composite material gradually increases. When the particulate volume fraction exceeds about 37 volume percent, the mass of composite material becomes semi-solid and freestanding. The resulting composite material may be further processed, as by forming to a useful shape or diluting with another matrix material.

Abstract: A composite material is rapidly melted by furnishing a pre-wetted composite material in the form of granules, placing the granules into an induction coil, and powering the induction heater to melt the metal matrix portion of the granules to form a molten mixture. High power inputs to the induction coil may be used, so that the granules are rapidly heated to their melting point and to temperatures above the melting point, from which the molten mixture may be cast. Because of the rapid heating, otherwise-reactive composite materials may be prepared by melting in air.

Abstract: The invention provides a new method for the determination of the concentration of gas dissolved in a molten metal or metal matrix composite employing a new immersion head probe in apparatus employing the method. Such determinations are needed to facilitate removal of the gas, which can cause loss of desirable properties and/or bubbles in the solidified material and subsequent processing difficulties. This determination is particularly difficult with metals containing high concentrations of particulate additions, such as metal matrix composites, since it is necessary to avoid deposition of the particulates and consequent inaccurate readings. The method employs apparatus which circulates an inert carrier gas through the probe in gas exchange contact with the molten metal to entrain dissolved gas until an equilibrium mixture is obtained; the concentration of the dissolved gas in the mixture then is representative of its concentration in the molten metal.

Abstract: Apparatus and method for studying particles suspended in an electrically conducting fluid by providing an aperture with a current path therethrough, causing the fluid to flow through the aperture and detecting resistive pulses caused by the passage of suspended particles. Additional information about particle size is generated by designing the aperture such that its cross-section changes progressively along its length, and observing the duration of the resistive pulses, which duration varies with particle size. The method is particularly useful for the study of particles suspended in molten metal.

Abstract: The invention provides a new immersion head probe for use in apparatus for the determination of the concentration of gas dissolved in a molten metal. Such determinations are needed to facilitate removal of the gas, which can cause bubbles in the solidified metal and subsequent processing difficulties. The apparatus circulates an inert carrier gas through the probe in gas exchange contact with the molten metal to entrain dissolved gas until an equilibrium mixture is obtained; the concentration of the dissolved gas in the mixture then is representative of its concentration in the molten metal. The head consists of a monolithic or integral body of a porous gas-permeable material of sufficient mechanical strength at the temperature of the molten metal and of sufficient porosity, pore size and permeability to permit the necessary gas diffusion in a reasonable period of time.

Abstract: The invention provides a new method and apparatus for the detection of non-conductive particulates in molten metals, such as aluminum, gallium, zinc and lead, that can be liquified and drawn into a suitable refractory container. The passage into the container is of very small diameter (about 300 micrometers for aluminum) and it forms part of a current path between two electrodes carrying a current of about 1 to 500 amperes. The path is surrounded by liquid metal which forms an effective Faraday cage screening the path, enabling the passage of a particulate of about 15 micrometers or larger to produce a voltage pulse between the electrodes of greater than 5 microvolts, which is detectable above the inevitable background noise, which is of about that value.

Abstract: The invention provides a new method and apparatus for the detection of non-conductive particulates in molten metals, such as aluminum, gallium, zinc and lead, that can be liquified and drawn into a suitable refractory container. The passage into the container is of very small diameter (about 300 micrometers for aluminum) and it forms part of a current path between two electrodes carrying a current of about 1 to 500 amperes. The path is surrounded by liquid metal which forms an effective Faraday cage screening the path, enabling the passage of a particulate of about 15 micrometers or larger to produce a voltage pulse between the electrodes of greater than 5 microvolts, which is detectable above the inevitable background noise, which is of about that value.