Hot chamber process
In the hot-chamber process (die casting), the shot chamber sits permanently in the molten metal. It only works with low-melting-point alloys like zinc—so die and machine stresses differ from the cold-chamber process.
What the Hot Chamber Process Is
In the hot chamber process, the die chamber is permanently immersed in the molten metal. A piston pushes the metal through the gooseneck into the die – fast, simple, and with short cycle times.
Why Only Low-Melting Alloys
A steel chamber would be attacked by aluminum at 650 °C immediately. That's why the hot chamber process only works with zinc and similar low-melting alloys – usually around 400–450 °C.
What This Means for the Die
Zinc die-casting dies see lower pouring temperatures than aluminum dies. The thermal shock is less, but still there. Hot work steels like 1.2343 and 1.2344 are also standard here because they combine hot strength with toughness.