A casting method of an active metal includes, in an induction melting furnace using a water-cooled crucible, tapping a molten metal into a mold from a tapping hole provided at a bottom of the water-cooled copper crucible to cast an ingot of the active metal. In conducting the casting under a casting condition in which the ingot has a diameter (D) of 10 mm or more and a ratio (H/D) of an ingot height H to the ingot diameter D of 1.5 or more and a weight of the molten metal tapped in the casting is 200 kg or less, a temperature of the molten metal in the casting is set to be higher than the melting point of the active metal and a casting velocity V (mm/sec) is controlled to satisfy V≤0.1H in relation with the ingot height H by adjusting an opening diameter of the tapping hole.

A vacuum system for a die casting mold, which forms vacuum inside a cavity formed between a fixed mold and a movable mold, includes: a ventilation assembly disposed between the cavity and a vacuum pump and mounted between the fixed mold and the movable mold and configured to decrease a flow rate of molten metal when the molten metal filled in the cavity flows in; and a vacuum pump forming the vacuum inside the ventilation assembly.

A vacuum system for a die casting mold, which forms vacuum inside a cavity formed between a fixed mold and a movable mold, includes: a ventilation assembly disposed between the cavity and a vacuum pump and mounted between the fixed mold and the movable mold and configured to decrease a flow rate of molten metal when the molten metal filled in the cavity flows in; and a vacuum pump forming the vacuum inside the ventilation assembly.

A piston of a die-casting apparatus includes: a piston tip having a generally cup-shaped body having an inner front face and an inner cylindrical surface, the inner front face having a plurality of grooves formed therein for conveying cooling fluid; and an inner piston carrier coupled to the piston tip, the carrier comprising an elongate forward portion matingly engaging the piston tip.

A piston of a die-casting apparatus includes: a piston tip having a generally cup-shaped body having an inner front face and an inner cylindrical surface, the inner front face having a plurality of grooves formed therein for conveying cooling fluid; and an inner piston carrier coupled to the piston tip, the carrier comprising an elongate forward portion matingly engaging the piston tip.

A counter gravity casting apparatus includes a reusable metal mold having a plurality of mold cavities, a feed tube configured to feed molten alloy into the mold, and a vacuum fitting configured to permit a vacuum to be applied to the mold. The mold includes multiple metal sections configured such that adjacent metal sections mate to one another, the metal sections being separable from one another. The metal sections include recesses that form the mold cavities, and the mold includes a sprue and multiple runner passages. The sprue is configured to receive molten alloy from the feed tube, and the multiple runner passages are configured to feed molten alloy from the sprue to the mold cavities. Methods of casting bulk amorphous alloy articles or feedstock is described.

A counter gravity casting apparatus includes a reusable metal mold having a plurality of mold cavities, a feed tube configured to feed molten alloy into the mold, and a vacuum fitting configured to permit a vacuum to be applied to the mold. The mold includes multiple metal sections configured such that adjacent metal sections mate to one another, the metal sections being separable from one another. The metal sections include recesses that form the mold cavities, and the mold includes a sprue and multiple runner passages. The sprue is configured to receive molten alloy from the feed tube, and the multiple runner passages are configured to feed molten alloy from the sprue to the mold cavities. Methods of casting bulk amorphous alloy articles or feedstock is described.

A method for vacuum smelting and variable pressure solidification forming aluminum alloy piece with ultra-thin wall and high gas tightness is provided, in which an induction heating furnace is set in a vacuum tank, a quartz crucible with thickness of 58 mm is used; a preheated aluminum alloy ingot is placed in the crucible, side doors of the tank is closed, and a vacuuming processing is performed for the tank; the melt is filled from the bottom layer of the casting; when the melt reaches to the top, the main valve and the air-release valve are turned on until the inside and outside pressures are consistent, and then the casting is taken out. The requirement of high air tightness for vacuum tank is reduced, and aluminum alloy casting with high quality can be obtained at lower cost.

A method for vacuum smelting and variable pressure solidification forming aluminum alloy piece with ultra-thin wall and high gas tightness is provided, in which an induction heating furnace is set in a vacuum tank, a quartz crucible with thickness of 58 mm is used; a preheated aluminum alloy ingot is placed in the crucible, side doors of the tank is closed, and a vacuuming processing is performed for the tank; the melt is filled from the bottom layer of the casting; when the melt reaches to the top, the main valve and the air-release valve are turned on until the inside and outside pressures are consistent, and then the casting is taken out. The requirement of high air tightness for vacuum tank is reduced, and aluminum alloy casting with high quality can be obtained at lower cost.

A casting method includes preparing a thin shell mold which is sintered and placed in a box. Sands are buried in the box to encompass the thin shell mold. The pressure chamber is depressurized. The casting material is filled into the thin shell mold, such that the thin shell mold is disposed at a vacuum state. Then, the negative pressure of the pressure chamber is released. Then, the pressure chamber is pressurized, to form a pressure difference which presses the casting material to flow into the thin shell mold, thereby finishing the casting work. The temperature of the casting material is reduced, and the pressure in the pressure chamber is increased. Then, the casting material is cooled to form a casting product. Then, the thin shell mold is broken, and the casting product is removed.