Cold chamber process
In the cold chamber process (die casting), the liquid metal is dosed from outside into the casting chamber because it would otherwise attack the machine. This is how aluminum and magnesium are cast – with the highest thermal loads on the mold.
What the Cold Chamber Process Is
In the cold chamber process, the molten metal is not held in the machine but is dosed from outside into the casting chamber per shot. A plunger then presses it into the mold.
Why This Detour
Aluminum and magnesium attack steel at their high temperatures – a chamber permanently in contact with the metal would be destroyed. Therefore, the metal is dosed only shortly before the shot.
The Highest Mold Load
Aluminum enters the mold at around 650 °C, under high pressure, and is then cooled. This cycle creates fire cracks on the mold surface. Therefore, the cold chamber mold requires hot-work tool steels with maximum hot strength and fire crack resistance – classic grades 1.2343 and 1.2344, and for highest demands 1.2367.