Aluminium: bend, roll or form?
Finished parts can have complex internal and external geometries, with an exceptionally smooth surface finish, so that only minimal secondary processing is needed
Compared to traditional forming methods, cold forming of aluminium can give quality parts in high volumes with a good surface finish that need only minimal secondary operations, says Dawson Shanahan.
Shaping or forming aluminium is generally carried out using rolling, machining or hot forming processes. Although each has its benefits they can require significant amounts of energy, produce high volumes of waste material, leave a poor quality surface finish or adversely affect the mechanical characteristics of the finished part.
By comparison, precision cold forming, although not widely used for manufacturing aluminium parts, offers a number of important benefits.
A cold forming press uses advanced mould and die sets, combined with extremely high levels of applied pressure (in excess of 200 tonnes) to extrude the metal to the desired shape. Finished parts can have complex internal and external geometries, with an exceptionally smooth surface finish, so that only minimal secondary processing is needed. As extrusion follows the grain boundaries the strength to weight ratio of cold formed parts is also far higher than that of machined components, while the amount of waste material is reduced by more than 75%.
Just as importantly, cold forming consumes minimum energy and is achieved quickly, making it possible to produce high quality parts in large volumes, typically up to 300 units/minute from a single press. With the pressure on manufacturers to control costs, Dawson Shanahan says cold forming is a process that is now worth greater consideration.
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