Die Casting – design guide, materials, advantages and disadvantages

PDC process diagram. Image is © 2018 EngineeringClicks

Die casting is a permanent mould casting process in which molten metal is poured into a mould and removed after solidification. There are two main types of this process: Gravity Die Casting (GDC) and Pressure Die Casting (PDC). In GDC, molten metal is poured into the mould using gravity. In PDC, the molten metal in injected into the mould under pressure. PDC is further divided into two types: Cold Chamber Die Casting and Hot Chamber Die Casting. Following are some of the general steps performed in Die Casting:

1.    Raw metal is melted so it can be poured or injected into the mould cavity.
2.    Except for Cold Chamber Die Casting, moulds are heated before introducing the molten metal.
3.    The moulds are closed and molten metal is poured or injected into the mould.
4.    The moulds are left closed until the molten metal solidifies.
5.    The moulds are opened and the cast part is removed

GDC process diagram. Image is © 2018 EngineeringClicks


What materials can be Die Cast?

Both types of Die Casting are used for the processing of non-ferrous metals including magnesium, copper and aluminum. Additional metals like nickel, iron and lead can be used for GDC.

Design Considerations

Ingots of LM6 aluminium alloy ready to be Die Cast

Process Variations

Economic Considerations

A Die Cast automotive part featuring post-machined surfaces

Quality Considerations

Advantages and Disadvantages of Die Casting

Advantages: Production rate is moderate to high. Close tolerances are possible.
Disadvantages: Poor control over mechanical properties. Extra quantity of material required during the process.