 | 2005 |
Abstract:
Curved aluminium profiles with higher accuracy in reference to the cross section and the contour offer a wide application for lightweight construction. One field of application is the automotive industry whose worldwide production is at close to 60 million new units per year, with annual growth of about 3%. Each vehicle currently includes between 100 kg and 150 kg of wrought and cast aluminium products. It is particulary the material´s combination of lightweight and high strength that has allowed vehicle manufacturers to improve fuel efficiency and reduce emissions, without affecting safety. In transportation aluminium lightweight concepts of bring advantages to the fore such as reduced downtime, reduced wear and tear on brakes and tyres, and better fuel consumption. Likewise, most high-speed trains and metro trains are built from aluminium (Figure 1). Designs based on combining large extrusions, very strong wrought plates, and castings greatly help to reduce the weight of carriages. The space-frame-construction in the automotive industry focuses especially in low volume production on the usage of extruded aluminium profiles. For example in the displayed Audi A8 space-frame the weight ratio of extruded profiles accounts 22%. Half of these profiles are curved profiles which can be conventionally manufactured just with several treatments. Curved profiles will be produced conventionally by bending a straight extruded aluminium profile. The profiles manufactured in this process chain, straight extrusion, stretching and bending often can not come up with the required component properties.