Permanent mold

Usually metal but also ceramic molds which can be used repeatedly for casting and are not destroyed after casting. Metal permanent molds are also called dies. The permanent molds should not display a change to the surface quality or the geometrical dimensions in the production process.

Permanent molds are exposed to very high temperatures and changes in temperature (e.g. in brass pressure die casting), meaning that demanding requirements are set for their thermal conductivity and their resistance to changes in temperature.

Suitable materials for permanent molds are cast iron, steels (in particular hot-forming steel, e.g. 1.2343, 1.2344), brass, copper and heat-resistant graphite-clay mixtures. For low melting point metals, permanent molds made from light metals can also be used. Sintered hard metals or composites and refractory metals are also used in mold construction in individual cases. Metal permanent molds which are subjected to high temperature loads must be cooled (e.g. continuous casting dies, pressure die casting molds). To regulate the cooling rate of the casting in a targeted way and avoid high temperature gradients in the material, permanent molds are also pre-heated (s. a. Mold temperature).

Additional references:
Permanent moldcasting
Counterpressure casting process
Tilting gravity die casting process
Gravity die casting process
Low pressure gravity die casting process