Patent DE-102007060418-A1 (DE)
Title: Vacuum die-casting method for producing pore-free and heat treatable casting part by a die casting machine, comprises transporting melt from melt reservoir into casting chamber and pressing the melt over injection region in mold cavity
Inventor: BAUMANN MARTIN
IPC: B22D17/14
Filed: 2007-12-14
Abstract: The vacuum die-casting method for the production of pore-free and heat treatable casting part by a die casting machine with a casting chamber (6), a mold cavity (10), a melt reservoir (5) and casting piston, comprises interfering the piston into a first end of the tubular casting chamber, connecting the second end over a casting area (19) with the mold cavity, connecting the melt reservoir over a dosing tube (2) with the chamber, transporting the melt from the melt reservoir by evacuation over the dosing tube into the chamber and pressing the melt over the injection region in the mold cavity. The vacuum die-casting method for the production of pore-free and heat treatable casting part by a die casting machine with a casting chamber (6), a mold cavity (10), a melt reservoir (5) and a casting piston, comprises interfering the casting piston into a first end of the tubular casting chamber, connecting the second end of the casting chamber over a casting area (19) with the mold cavity, connecting the melt reservoir over a dosing tube (2) with the casting chamber, transporting the melt from the melt reservoir by the evacuation over the dosing tube into the casting chamber, ending the melt supply through pre-guiding the casting piston in the casting chamber and subsequently pressing the melt present in the casting chamber over the injection region in the mold cavity. The casting chamber is closed to the injection area for dosing the melt and directly evacuated and the melt is transported into the casting chamber. The melt supply is interrupted through the casting piston in the casting chamber and the melt present in the casting chamber is compressed. The connection of the casting chamber is opened to the injection area and the mold cavity, and the melt is pressed in the opened free area through the casting piston. A low pressure of 5-30 mbar is produced in the casting chamber. The degassing of the gas dissolved in the melt is carried out during dosing of the melt through the evacuation of the casting chamber. An inert gas atmosphere is formed in the area of the ends of the casting piston turned away from the casting chamber. The first end of the casting chamber is flooded up to the casting piston and the dosing tube with inert gas during pre-guiding of the casting piston and overrunning the mouth of the dosing tube. The casting chamber is filled by the evacuation over the dosing tube to 30-70%. The melt present in the casting chamber is completely compressed by the casting piston between a closure present in the second end of the casting chamber and an area present in between the casting chamber. The mold cavity including the injection area is evacuated by a second vacuum source. A low pressure of 50-200 mbar is produced in the area of the mold cavity including the injection area. The second vacuum source is disengaged when a certain filling grade of the mold cavity with the melt is reached. An independent claim is included for a device for vacuum die-casting for the production of pore-free and heat treatable casting part by a die casting machine.