Method and apparatus for making a thixotropic metal slurry
AssigneeBrunswick Corporation
InventorsSamuel M.D. Norville, Shaupoh Wang, Patrick J. Lombard
Life of this patent
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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.
Claims23
An apparatus for producing a semi-solid metallic slurry, comprising:
- a furnace adapted to contain molten metal;
- a mixing vessel for receiving, containing and cooling a mass of molten metal connected in fluid communication to the furnace;
- a stator assembly positioned around the mixing vessel;
- and
- a pressurized gas source connected in fluidic communication with the melting furnace;
- wherein actuation of the stator assembly produces a magnetomotive stirring force within the mixing vessel;
- and
- wherein the mixing vessel is adapted to controlledly cool a mass of molten metal to form a thixotropic slurry.
A device for producing a thixotropic metallic slurry, comprising:
- a melting furnace for containing molten metal under a controlled atmosphere;
- a pressurized inert gas supply fluidically coupled to the melting furnace;
- a mixing vessel in liquid communication with the melting furnace;
- a thermal jacket surrounding the mixing vessel and in thermal communication therewith;
- a stator assembly positioned around the mixing vessel and in magnetic communication therewith;
- emptying means for unloading the mixing vessel;
- wherein the melting furnace is substantially gas tight;
- wherein pressurized inert gas is flowed into the melting furnace;
- wherein actuation of the melting furnace loads the melting furnace with solid metal precursors and heats the solid metal precursors past their melting point;
- wherein increasing the gas pressure pushes molten metal into the mixing vessel;
- wherein actuation of the stator assembly generates a controlled magnetic stirring force to act on molten metal in the mixing vessel;
- wherein the controlled magnetic stirring force is sufficient to actuate controlled circulation of molten metal in the mixing vessel;
- wherein actuation of the thermal jacket allows controlled cooling of molten metal in the mixing vessel;
- wherein controlled cooling and circulation of molten metal in the mixing vessel enables formation of a semi-solid metal slurry therein.
A magnetomotive thixotropic slurry maker, comprising;
- a melting furnace adapted contain a metallic melt under an inert atmosphere;
- a volume of liquid metal contained in the melting furnace;
- means for providing an inert gas atmosphere in the melting furnace to prevent metallic oxide formation therein;
- a mixing chamber in fluidic communication with the melting furnace;
- pressure means for transferring at least a portion of the metallic melt into the mixing vessel;
- and
- means for controlledly cooling and stirring the at least a portion of the metallic melt in the mixing chamber to form a semi-solid metallic slurry having a degenerated dendritic structure.
A method for producing a thixotropic metallic melt, comprising the steps of:
- a) melting a solid metal precursor mass in a melting furnace;
- b) transferring liquid metal into a mixing chamber;
- c) stirring the liquid metal;
- d) cooling the stirred the liquid metal to form a thixotropic suspension of substantially spherical metallic particles of a first phase suspended in a liquid of a second phase;
- and
- e) transferring the thixotropic suspension from the mixing chamber;
- f) wherein the melting furnace is fluidically connected to the mixing chamber.
Dependencies are inferred from the claim text.