The foundry process is centuries old, and nowadays over 110 tonnes of castings are produced every year. Foundry is more than just making metal parts for engine, rail and pipe components. Nowadays, around 90% of all manufactured consumer products use metal castings for their module parts – the automotive industry is probably one of the largest industries which depend on the foundry sector.
A foundry or metal factory casts metals into shapes by melting them down and pouring the molten liquid into a sand, ceramic or metal mould to form geometrically complex parts. The metal is then allowed to cool and the liquid solidifies. The shaped metal, or casting, can now be used to produce more difficult and uniquely shaped products or parts.
All major metals can be cast. The most common metals processed are iron, aluminium, steel and copper-based alloys but other metals such as bronze, brass, magnesium and zinc can also be used to produce castings so that parts of any desired shape and size can be formed.
There are several stages involved in the casting process which include making the pattern, melting the metal, pouring the molten liquid, the cooling process, removing the metal, cleaning the parts and the inspection process.
Moulds are carefully shaped with a pattern, which is a wood or metal replica of the object to be cast so that the final shape corresponds fully with the mould used. Usually, moulds are made using silica sand, but they can be created using different materials depending on the type of metal being cast.