Aluminium, Copper and Zinc
Gravity Casting consists of heating up an oven above a mold, heating the mold to a similar temperature, and then slowly pouring the liquid metal into the mold. The advantage of this method of casting is very little air entrapment, because the metal is allowed to slowly degas. It also leads to very few shrinking cavities. The downside is that Gravity Casting is very expensive and time-consuming, and is therefore mostly used when there are high demands for the mechanical properties of the product, such as with aluminium wheels or dampers.
Best suited for: Products with high demands concerning the mechanical properties, such as aluminium wheels or dampers.
Steel Mold Casting
Steel Mold Casting consists of a steel mold with the shape of the part/product being filled with liquid metal, usually with a large spoon. This method results in a less refined surface, and is mostly desirable when the resulting product is to be welded or will receive heat treatment. As with Gravity Casting, this method leads to very little air entrapment, which is why Steel Mold Casting is an excellent choice when heat treatment is needed.
Best suited for: Products that need to be welded or will receive heat treatment.
Again, a steel mold is used to pour the metal. Behind the mold is a cylinder that fills it within mere milliseconds using liquid metal such as aluminium. This is much faster than Gravity Casting or Steel Mold Casting, but leads to less reliable mechanical properties and the resulting product cannot be welded or have heat treatment applied.
Best suited for: Aluminium products or zinc alloys like Zamac with no high demands for the mechanical properties of the product.