The lightweight construction megatrend is driven by new material and process developments utilising aluminium
Aluminium has transformed the automotive industry, and it will continue to do so in future. It offers a better cost-benefit ratio than any other material. By collaborating even more closely in future, aluminium producers, processors and vehicle manufacturers can unlock further potential for the use of aluminium.
Lightweight construction will continue to pose the greatest challenge for the automotive industry in future. The market for lightweight components made from high-tensile steel, aluminium and carbon-fibre-reinforced plastic is projected to grow to 300 billion euros by 2030, which is more than four times the size of the market in 2010. That is because reducing the weight of a vehicle by 100 kilograms lowers its fuel consumption by 0.3 to 0.5 litres per 100 kilometres, something that translates to anywhere from 8 to 11 grams less CO2 being released. Furthermore, lighter vehicles also boast better driving dynamics and comfort. The most important material for lightweight construction in the automotive industry is aluminium, and there is a growing demand for innovative solutions and applications employing aluminium materials.
Aluminium has transformed the automotive industry, and it will continue to do so in future. It offers a better cost-benefit ratio than any of the substitute materials on offer. By collaborating even more closely in future, aluminium producers, processors and vehicle manufacturers can unlock further potential for the use of aluminium here. The figures offer an impressive reflection of this trend. The average aluminium content of cars is steadily increasing. Whereas 60 years ago an average vehicle contained 19 kilograms of aluminium, between 1990 and 2014 the aluminium content of an average car nearly tripled, increasing from 50 kg to 140 kg. This figure is projected to increase to between 160 and 180 kg by 2020 as small and mid-size cars follow the trend set by luxury cars in the use of aluminium.
As the competition amongst materials intensifies, car manufacturers and aluminium suppliers have begun working together more closely. By investing in application-oriented research and development, the aluminium industry has succeeded in continually improving the properties of its materials, developing new products and optimising production processes. Process and material innovations drive the development of efficient lightweight construction solutions and their implementation in series production, as with energy-saving components for chassis, engines, transmissions and gearboxes.
The use of aluminium in automotive manufacturing is also being driven by new joining technologies. Improved soldering methods, for example, have resulted in a situation where nearly all heat exchangers for automotive air conditioning systems and radiators are now made of aluminium. Innovative welding processes and bonding technologies make it possible to create complex structures that are not only better in a technical sense, but which are also more economical. Applications even extend to entire axle systems.
3. New applications
In recent years, aluminium producers and processors have developed a series of new aluminium alloys (5xxx, 6xxx) with improved mechanical properties, including better strength, formability and corrosion resistance, allowing them to offer to ever lighter components with reduced wall thicknesses. Thanks to their good workability, high strength values and excellent weldability, innovative aluminium materials have made their way into new areas of application. The development of new roller surface geometries and lubricants for the improvement of tribological properties is also moving full speed ahead.
Developments in the field of e-mobility are also propelling use of this material, as power electronics, e-motors and especially batteries and the battery housings that protect them against external influences are creating further potential for the use of lightweight construction in vehicles. As a result of electronic vehicles’ different design requirements, there are many new products and applications for which aluminium profiles are the only sensible option, due to the possibilities for functional integration or cooling, for instance. Light metal solutions are winning out in battery housings, structural components and drive systems.
The automotive industry is one of the biggest drivers of material and process development for aluminium, whereby it is less the end customers themselves, but rather society as a whole and the regulatory framework that are pushing these developments forward. Increasing urbanisation, such as in Asia, is forcing carmakers to come up with new concepts, while threshold values for the fuel consumption of each automotive manufacturer's range of vehicles are also having an impact. As a result of all these factors, the demand for innovative lightweight construction solutions in the vehicle manufacturing industry will continue to increase.
Thanks to growing demand for ‘sharp-edged’ designs for automotive exteriors, 6xxx materials with excellent formability properties are urgently needed. As a result of lightweight construction and the reductions in sheet thickness that this entails, materials must offer high strength values. The specific requirements of automotive manufacturers vary. On the one hand, high strength and good crash performance, such as with ductility, are required, whereas only the highest stiffness levels can satisfy the rigidity requirements of the chassis. Depending on the use to which a component is to be put and expansion possibilities, good formability related to strength and geometry is expected in the various strength classes.
Overall, the automotive sector offers the prospect of exponential growth for the aluminium industry, with demand and requirements for aluminium continuing to grow. Even if aluminium should lose market share in individual areas of application, it will find increasing employment in others, and its growth areas will remain larger than the areas in which substitutes are found.
In future, aluminium sheet will take the place of other materials, such as steel for the vehicle’s exterior and hang-on parts, and OEMs have already made it clear that the use of aluminium will increase for bonnets, fenders and doors in the next generations of vehicles. Cast aluminium also remains an important and dynamic growth market. Aluminium founders have a wealth of materials expertise, and complex cast parts with high machining depth offer tremendous potential. The utilisation of aluminium solutions in crash-relevant areas of the chassis also represents a field with outstanding potential for the future.