Abstract: A method of producing on-demand, semi-solid material for a casting process includes the steps of first heating a metal alloy until it reaches a molten state and maintaining that molten state within a desired temperature range. The next step is to ladle out a portion of the molten alloy and transfer it into a processing vessel. In one arrangement the vessel is configured with its own cooling arrangement so as to begin the solidification process for the molten alloy. In another embodiment, a thermal jacket is used to facilitate the cooling of the vessel and accordingly the cooling of the molten alloy. The next step is to apply an electromagnetic field to the molten alloy in order to create a stirring action which results in a desired flow pattern of the molten alloy within the vessel. The electromagnetic stirring begins as soon as the molten alloy is placed in the vessel and continues while the cooling continues in order to create a slurry billet of the desired metallurgical composition.

Abstract: The present invention provides a method for solving the Navier-Stokes equation of viscous, incompressible laminar flows with moving free surfaces in complex domains. The method uses fixed mesh control volume-finite element techniques to track the flow. A gauss point velocity vector is defined as the average of its nodal counterpart, such that the gauss point velocity vector is constant over the element. The gauss point velocity vector is then inserted into the continuity constraint to form the Poisson pressure equation for solving the pressure field. The solution to the Poisson pressure equation is unique, the common checker-board problem is therefore eliminated. The corrected pressure field is substituted into the momentum equations, so that the resulting velocity field satisfies the continuity equation. Since velocity and pressure are evaluated at the same order, the global mass conservation can be evaluated to machine round-off tolerances.

Abstract: An apparatus for and method of controlling the cooling rate of a metallic melt in the production of a semi-solid slurry billet for use in a casting process. The apparatus comprises a thermal jacket including symmetrical halves, with each half having a rounded heat transfer surface extending between a pair of longitudinal edges. An actuator mechanism engages the heat transfer surfaces into intimate contact with a vessel containing the metallic melt to effectuate conductive heat transfer between the vessel and the thermal jacket, with the pairs of longitudinal edges of each halve being disposed in a generally opposite, spaced relationship. The thermal jacket includes a plurality of passageways adapted to carry cooling air for extracting heat from the metallic melt, and a plurality of electric heating elements for adding heat to the metallic melt. The cooling rate of the metallic melt is controlled within a range of about 0.

Abstract: An apparatus for producing a thixotropic metallic melt by simultaneously controlledly cooling and stirring the melt to form solid particles of a first phase suspended in a residual liquid second phase. Vigorous stirring of the metallic melt results in the formation of degenerate dendritic particles having substantially spheroidal shapes. The metallic melt is stirred to rapidly and efficiently circulate the forming semi-solid slurry. Circulation of the forming semi-solid slurry results in a substantially uniform temperature throughout. Through precision stirring and cooling, a semi-solid slurry is formed having a first solid phase of about 70-80 wt. % suspended in a second liquid phase.

Abstract: A method and apparatus for stirring a molten thixotropic aluminum alloy comprising a first solid particulate phase suspended in a second liquid phase so as to maintain its thixotropic character by degenerating forming dendritic particles into spheroidal particles while simultaneously equilibrating the melt temperature by quickly transferring heat between the melt and its surroundings. The melt is stirred by a magnetomotive force field generated by a stacked stator assembly. The stacked stator assembly includes a stator ring adapted to generate a linear/longitudinal magnetic field positioned between two stator rings adapted to generate a rotational magnetic field. The stacked stator rings generate a substantially spiral magnetomotive mixing force and define a substantially cylindrical mixing region therein.

Abstract: A container system including a vessel for holding a thixotropic semi-solid aluminum alloy slurry during its processing as a billet and an ejection system for cleanly discharging the processed thixotropic semi-solid aluminum billet. The crucible is preferably formed from a chemically and thermally stable material. The crucible defines a mixing volume. The crucible ejection mechanism may include a movable bottom portion mounted on a piston or may include a solenoid coil for inducing an electromotive force in the electrically conducting billet for urging it from the crucible. During processing, a molten aluminum alloy precursor is transferred into the crucible and vigorously stirred and controlledly cooled to form a thixotropic semi-solid billet. Once the billet is formed, the ejection mechanism is activated to discharge the billet, from the crucible. The billet is discharged onto a shot sleeve and immediately placed in a mold and molded into a desired form.