Abstract: The present invention relates to a technique for forming silicon carbide coated porous filters for use in filtering molten metal, especially copper and copper alloy melts. The technique comprises preparing a silicon carbide containing slurry having a viscosity in the range of about 1 to about 50, preferably from about 5 to about 30, centipoise and impregnating a rigid porous substrate material with the slurry. In a preferred embodiment, the slurry contains mono-aluminum phosphate as a binding agent, ethylene glycol as a wetting agent, powdered silicon carbide having a maximum settling rate of about 0.1 mm./min. and the balance essentially water. After draining of the excess slurry, the coated substrate material is heated to substantially prevent foaming of the coating during firing and fired to bond the silicon carbide coating to the substrate material.

Abstract: A method and apparatus for casting a grain refined ingot from a metallic melt supplied to a casting mold through a feed tube. The feed tube is provided with at least one cooling passageway through which a cooling fluid cyclically flows to form a zone of fine dendrites on the inner peripheral surface of the mold. An inductor is provided to reheat the zone of fine dendrites to detach dendrite arms into the melt which serve as nuclei for grain refinement as the melt solidifies into a cast ingot in the mold.

Abstract: The present invention relates to a technique for forming silicon carbide coated porous filters for use in filtering molten metal, especially copper and copper alloy melts. The technique comprises preparing a silicon carbide containing slurry having a viscosity in the range of about 1 to about 50, preferably from about 5 to about 30, centipoise and impregnating a rigid porous substrate material with the slurry. In a preferred embodiment, the slurry contains mono-aluminum phosphate as a binding agent, ethylene glycol as a wetting agent, powdered silicon carbide having a maximum settling rate of about 0.1 mm./min. and the balance essentially water. After draining of the excess slurry, the coating substrate material is heated to substantially prevent foaming of the coating during firing and fired to bond the silicon carbide coating to the substrate material.

Abstract: The present invention relates to a technique for forming silicon carbide coated porous filters for use in filtering molten metal, especially copper and copper alloy melts. The technique comprises preparing a silicon carbide containing slurry having a viscosity in the range of about 1 to about 50, preferably from about 5 to about 30, centipoise and impregnating a rigid porous substrate material with the slurry. In a preferred embodiment, the slurry contains mono-aluminum phosphate as a binding agent, ethylene glycol as a wetting agent, powdered silicon carbide having a maximum settling rate of about 0.1 mm./min. and the balance essentially water. After draining of the excess slurry, the coated substrate material is heated to substantially prevent foaming of the coating during firing and fired to bond the silicon carbide coating to the substrate material.

Abstract: A copper or copper alloy material having a reduced number of defects is formed by removing impurities from the material while in a molten state with a member having exposed silicon carbide particles. The member may be a bed filter formed from bed media having exposed silicon carbide particles, a porous body formed from a slurry containing silicon carbide, a porous body having at least one melt contacting surface coated with a silicon carbide material, and/or a lining having at least one melt contacting surface coated with a silicon carbide material.

Abstract: A copper or copper alloy material having a reduced number of defects is formed by removing impurities from the material while in a molten state with a member having exposed silicon carbide particles. The member may be a bed filter formed from bed media having exposed silicon carbide particles, a porous body formed from a slurry containing silicon carbide, a porous body having at least one melt contacting surface coated with a silicon carbide material, and/or a lining having at least one melt contacting surface coated with a silicon carbide material.

Abstract: A copper or copper alloy material having a reduced number of stringer defects is formed by removing iron-containing components from the material with a member having exposed silicon carbide particles while the material is in a molten state. The member may be a bed filter formed from bed media having exposed silicon carbide particles, a porous body formed from a slurry containing silicon carbide, a porous body having at least one melt contacting surface coated with a silicon carbide material, and/or a furnace or passageway lining having at least one melt contacting surface coated with a silicon carbide material.