Die casting is one of the most economical and quickest forming processes. The advantages of this production process are that hundreds of thousands of castings can be produced relatively quickly by using just one mold. All components produced have a uniform quality and involve relatively low unit costs. Depending on the melting point of the metal, choose high pressure or low pressure die casting.
Materials
In die casting, non-ferrous metals are used to manufacture components, and the choice of alloy for a particular application depends on budget, weight and material properties.
Aluminum is one of the most important materials with a share of more than 80 %, followed by zinc and magnesium. However, copper, lead and tin can also be used. The alloys have different properties. For example, aluminum (600°C) and magnesium (520°C) have a high melting point, zinc (380°C) and lead (320°C) a low melting point.
Die casting alloys offer many advantages:
Low Pressure vs. High Pressure Die Casting
Various processes are used in foundry practice. Castings can also be produced without high pressure. In the sand casting process, for example, the alloy is poured into a mold made of sand, which must be destroyed in order to reveal the manufactured component (lost foam). In investment casting, which is used to manufacture very small cast parts, the molds and models (usually made of wax or plastic) are also destroyed after the casting process. Another example is Gravity Die Casting, which uses a permanent metal mold but does not use high pressure to press the melt into the mold. Rather, the casting is manufactured or the mold filled by gravity.
There are also differences in the die casting process. For example, there are processes that use either high or low pressure to produce the components. While high-pressure die casting accounts for around 50 % of light metal casting production, low-pressure die casting only accounts for just under 20 % of total production.
Low pressure die casting primarily uses alloys with low melting points. It is possible to casting components from 2 to 150 kg. The advantages are that very high strength values and complex geometries as well as improved material utilization and dimensional accuracy can be achieved. The process is less suitable for very thin-walled parts, since only a minimum wall thickness of 3 mm can be obtained. It should also be mentioned that casting cycles using low pressure die casting are slower than those under high pressure.
Fields of Application
Die casting is mainly used for large series production, i.e. for many components of the same type to be cast. Despite the high pressure used during the manufacturing process, a high casting quality is achieved. The die casting process is particularly suitable for the production of very thin (up to 1 mm) (lightweight) components.
Most commonly, die cast components are manufactured for the automotive industry, such as wheels, blocks, cylinder heads, valve blocks and manifolds. This sector accounts for around 84 % of the castings produced by German foundries. 3 The use of aluminum parts leads to a reduction in the weight of the vehicles and thus to a reduction in fuel consumption. In addition, there are other industries in which die cast parts are used:
In the future, other industries such as electromobility will be of interest to foundries. This offers enormous potential for light metal castings.