Basically, there are two types of die casting methods are employed in automotive industry.
1. Gravity Die Casting:
Molten metal (Al alloy like LM6 grade) is poured into the die, molten metal occupies the cavity space within. If the part has to be hollow – then a sand core is also required, it will placed in the die cavity. Sometimes, in order to ensure proper metal flow, the pouring set-up may be titled at an angle. This set-up is called ’tilt pour GDC’
Example: Pipe like structures component, spacers, intake manifolds or air intake elbow.
2. Pressure Die Casting
When the sections of the required casting are quite intricate, or the wall thickness specified is quite thin, this comes into the picture. In such case, one can't ensure the molten metal fills the die cavity properly, under the influence of gravity alone. In such a case, the metal is forced in to the die cavity under the application of pressure. The set-up used can be high pressure die casting (HPDC) or low pressure die casting (LPDC). Castings made by HPDC route generally have sound consistency for dimensions with close tolerance like +/- 0.2 mm. This precision of dimensions can't be expected in GDC or even in LPDC.
Example: Cylinder head cover for small engines, timing gear housing, gear box housing.