Kokillenguss

Kokillenguss, or permanent mold casting, is a metal casting process that uses a reusable metal mold, called a kokille, to shape molten metal. The kokille is typically made of steel or cast iron and may be coated or ceramic-lined to improve surface finish and reduce sticking. Unlike sand casting, the mold is not consumed during casting and can be used for many cycles, enabling higher production rates and tighter dimensional tolerances.

In the process, the mold is preheated to reduce thermal shock, and molten metal is poured into the kokille by gravity or with assistive forces such as low-pressure injection. After controlled cooling and solidification, the mold is opened and the casting is ejected. Runners, risers, and vents are incorporated to feed the casting and vent gases.

Common alloys for Kokillenguss include aluminum and magnesium alloys, zinc, and copper alloys. The method is well suited for light metals and parts with simple to moderately complex geometries. The main advantages are a good surface finish, high dimensional accuracy, relatively thin walls, and high production rates with repeatable quality. The approach also allows automation and reduced post-processing compared with some other methods.

Limitations include high initial tooling costs and mold wear, restrictions on complex geometries due to mold design, and sensitivity to shrinkage or porosity if cooling and venting are not properly controlled. The technique is widely used in automotive, consumer electronics, and industrial components where consistent quality and tolerances are important.