Both casting and forging can be used for manufacturing automobile hub.
In general, two methods are used to cast automobile hub: gravity casting and low pressure casting.
The process of gravity casting is quite simple. Pour liquid alloy into casting mould, then, cool the alloy into form. Casting mould has good wearing resistance and simple technology. Casting is the processing method which has the least cost. Low pressure casting refers to use low pressure to press liquid alloy into casting mould, making molecular distribution more average and fewer holes. For higher density, the hub has higher intensity and higher security coefficient. The mould can be more complicated.
Advantages of casting hub: casting hub has low price and it has no limitations on mould. The hub can bend after being hit, thus not easy to be ruptured.
Forging hub refers to use high pressure to press a piece of alloy into blank, then, use CNC for the secondary processing. For the mould having been impacted by high pressure, the molecules inside alloy are smaller, finer gap, higher density and stronger interaction force between different molecules. For this, only a few materials can realize sufficient rigidity, reducing the whole weight. The metal is still solid during forging. Therefore, mould has few variations just as liquid casting. Most of forging hubs have simple thick lines. Forging can eliminate as cast loosen inside metal caused during smelting and optimize microstructure. Meanwhile, mechanical properties of forging parts are better than those of casting parts, because of storing complete metal streamline. Forging parts are mainly used as key components in machinery which has high load and rigorous working conditions, except for simple rolling boards, bars or weld assemblies.
Advantages of forging hub: light weight, high rigidity.