Permanent mold casting
Permanent mold casting, also known as chill casting, is a production process in which the melt is poured into the cavity of a permanent molding tool, usually made from metal. This molding tool is also called a “chill” and belongs to the class of reusable or permanent molds which survive the casting process intact. Several thousands of cast parts can be produced with a single permanent mold. This lends a high degree of repetitive accuracy to parts produced with this method.
How does the permanent mold casting process work?
In permanent mold casting a distinction is made between different casting methods. The simplest form is the gravity process. This process is ideal for alloys with a low smelting point and also, for example, for aluminium. The permanent mold is usually made of two parts, with a negative of the cast part engraved/imprinted on the inside.
The molten alloy is poured into the mold. The hot, liquid metal cools and solidifies where it comes into contact with the inside of the mold. After a short period, the remainder of the molten metal, which has not solidified yet, is poured back out of the mold. As soon as the casting part has fully cooled, it can be released from the mold.
Another method is the low pressure process, in which the melt is not poured into the mold from above but rather pressed into the mold from below through a tube. This method is more complex but also yields particularly dense, non-porous, high-quality casting parts.
What are the advantages of permanent mold casting?
Since this casting method uses a permanent mold, it is possible to produce many thousands of identical component parts with the same mold. Apart from this, permanent mold casting offers many other advantages, including:
- Dimensional accuracy
- High structural density
- Good repetitive accuracy
- Smooth, high-quality surfaces
- The production of thin-walled components for weight optimization
- Good mechanical material characteristics due to fast cooling rates
Which materials can be used for permanent mold casting?
Alloys with a low smelting point are particularly suited for the permanent mold casting method, including:
- Silicon tombak
The most important information at a glance
Component: 0.02–30.0 kg
Dimensions: Depending on size and weight
Tolerances: According to BDG directive, VDG code of practice P690 D1-D3
Quantities: Medium-sized and large batches