Semi-solid casting apparatus and method

An apparatus for delivering heated metal to a die casting device for the manufacture of molded metal castings, the die casting device comprising dies forming at least one cavity having a vacuum gate and a metal feed gate, the apparatus comprising:

• a source of molten metal wherein the temperature of the molten metal is maintained at a predetermined temperature range above the temperature at which it will begin to solidify;
• a temperature controlled vessel maintaining the metal in a semi-solid state wherein up to about 45% of the metal is suspended as particles in a fluid fraction of the metal;
• a heated suction tube;
• a shot sleeve in a metal flow communication with the vessel through the heated suction tube, the shot sleeve communicating with the cavity through the metal feed gate and having a plunger reciprocally disposed in the sleeve to force semi-solid metal in the sleeve under pressure into the cavity;
• a vacuum source communicating with the vacuum gate, cavity, feed gate and shot sleeve to draw semi-solid metal from the temperature controlled vessel through the heated suction tube into the sleeve in a position to be forced by the plunger into the cavity, wherein the vessel comprising a bottom, a side wall, and a top, and further comprising an agitator disposed in the vessel and a heater positioned to deliver heat to semi-solid metal in the vessel through the bottom of the vessel and the bottom of the vessel includes an independently dimensioned heating chamber in metal flow communication with the semi-solid metal in the vessel through the bottom of the vessel and the heater is positioned to heat metal in the heating chamber.