Cast aluminum
Aluminum casting is the casting of aluminum alloys that are supplied in various master alloys . After melting, the properties of the material can be specifically influenced by adding various alloy elements that are introduced into the liquid aluminum. These properties are hardness , vibration absorption , toughness and machinability for mechanical processing. The following elements are used as alloy additives for motor housings and gear housings : copper , silicon , magnesium and the like. a. in question.
Various methods are used for casting:
- In continuous casting , a cast slab is made from liquid aluminum , which can be rolled after the homogenization annealing and milling of the segregation zones .
- Due to its low melting point, aluminum can also be processed well in die casting and especially in aluminum die casting , which is mainly done in the automotive industry (engine block, injection pump housing , cylinder head ). Here, aluminum offers advantages over iron , primarily because of its good thermal conductivity .
- If internal stresses pose a problem for the use of the cast components (e.g. pistons for internal combustion engines), permanent mold casting must be used, which, however, achieves lower productivity and increases the risk of cavities .
A very frequently used casting alloy is EN AC-AL Si9Cu3 (i.e. 9 mass percent silicon , 3 mass percent copper ), which can be hardened and reworked easily.