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AssigneeAluminum Company of America
InventorsHo Yu, Douglas A. Granger
Estimating the term…
A process and an apparatus are disclosed for reducing macrosegregation adjacent to a longitudinal centerline of a solidified cast body. Such cast bodies are preferably large size aluminum alloy ingots made in a continuous casting mold. The ingot is formed from a pool of molten metal having flow currents present therein. The flow currents tend to detach the tips of dendrites growing around the edge of the liquid pool and transport them to the center of the ingot. These detached dendrites, which are lean in eutectic elements, cause negative macrosegregation of the cast ingot. The process includes the step of weakening the magnitude of the flow currents within the liquid pool by placing a mechanical damper therein. The mechanical damper reduces shear acting on the dendrites and minimizes detachment and transport of dendrite particles to the center of the solidified body. The magnitude of the flow currents can also be reduced by increasing the metal head of the liquid pool or by reducing the kinetic energy of newly added molten metal. The apparatus claims a mechanical damper consisting of two or more parallel plates or concentric rings which extensively increases the surface area within the liquid pool. The plates or rings are spaced apart so as to provide flow passages for the molten metal which encourages laminar flow and tends to reduce turbulence within the pool.
A process for reducing macrosegregation adjacent to a centerline of a solidified body, said body being formed from a pool of molten metal having flow currents present therein, said liquid pool having dendrites which are lean in eutectic elements growing about the periphery thereof as said molten metal solidifies, said process comprising the step of weakening the magnitude of said flow currents by placing a mechanical damper in said pool, said damper including at least three plates connected together to form at least two passageways therebetween through which said molten metal can flow, said damper reducing shear stress acting on the tips of said dendrites and thereby reducing breakage and transport of particles of said dendrites to the center of said solidified body.
A process for reducing macrosegregation adjacent to a longitudinal centerline of a solidified body formed from a liquid pool of molten metal in a continuous mold, said liquid pool having dendrites which are lean in eutectic elements growing about the periphery thereof as said molten metal solidifies and having both natural and forced convection currents present therein, said process comprising the step of increasing the frictional surface area within said liquid pool to slow the velocity of said convection currents by placing a damper in said pool, said damper having at least two circular rings with a passageway formed therebetween through which said molten metal can flow, said damper providing an increased surface area for reducing turbulence within said liquid pool and minimizing the breakage of the tips of said dendrites and the transport of particles of said dendrites to the center of said solidified body.
A process for reducing macrosegregation adjacent to a longitudinal centerline of a solidified body formed from a liquid pool of molten metal, said liquid pool having strong convection currents present therein, and a mushy zone formed between said liquid pool and said solidified body, said process comprising the step of weakening the magnitude of said strong convection currents by placing a mechanical damper in said liquid pool to increase the internal friction therein without disturbing said mushy zone, said damper having at least three plates with a passageway formed between adjacent plates through which said molten metal can flow and attachment means for adjusting the depth to which said damper is positioned within said liquid pool.
A process for changing macrosegregation along a longitudinal centerline of a solidified aluminum alloy ingot formed in a continuous casting mold from a liquid poolof molten aluminum alloy having convection flow currents present therein, said liquid pool having dendrites which are lean in eutectic elements growing about the periphery thereof as said molten aluminum alloy solidifies, said process comprising the steps of:
An apparatus for reducing macrosegregation in a solidified body formed in a mold from a liquid pool of molten metal having flow currents present therein, said apparatus comprising:
The apparatus of claim 23 wherein said plates increase in size as one approaches a center plane which passes vertically through said damper.
An apparatus for reducing macrosegregation adjacent to a longitudinal centerline of a solidified body formed in a continuous mold from a liquid pool of molten metal having flow currents present therein, said apparatus comprising:
An apparatus for reducing macrosegregation adjacent to a longitudinal centerline of an elongated circular ingot formed in a continuous mold from a liquid pool of molten aluminum alloy having flow currents present therein, said apparatus comprising:
An apparatus for reducing macrosegregation along a longitudinal centerline of a solidified body formed in a continuous mold from a liquid pool of molten metal having flow currents present therein, and a mushy zone formed between said liquid pool and said solidified body, said apparatus comprising:
An apparatus for reducing macrosegregation adjacent to a longitudinal centerline of an elongated rectangular ingot formed in a continuous mold from a liquid pool of molten aluminum alloy having flow currents therein, said apparatus comprising;
Dependencies are inferred from the claim text.