Integrated hardening and sheet pressforming of aluminium

The transport section is under constant pressure to produce innovative lightweight solutions that improve vehicle fuel consumption and consequently lower CO2-emissions. Material substitution represents one of the main ways to save vehicle weight and substituting steel with aluminium is a straightforward solution. However, to retain the same properties as the corresponding steel part, the aluminium solution will potentially be somewhat bulky and take up more of the total volume of the car. This can represent a drawback, in particular in cases where extra space is needed for energy solutions. To be cost-competitive within production of parts for automotive applications, Raufoss Aluminium Neuman (RT) is dependent on innovations with respect to technology. To obtain effective production, resulting in a high number of produced parts per employee, focus on process control is important. Automated production is the key to implementing solutions generated at the interface between material, design and process. In the present project an automated and effective method for forming of age-hardenable alloys has been developed by RT in collaboration with AP&T, Hydro and SINTEF. The development has involved investigations of suitable alloys for the method as well as design and building of a production line. The innovation will enable production of chassis components with a slimmer design compared to today's aluminium solutions. It provides opportunities for improved formability of high strength alloys while maintaining good ductility. In addition, the integrated process will result in an increased productivity and reduced energy consumption per manufactured part. Calculations done as part of the project has shown that the method has the potential to reduce chassis-weight by 50%. Based on results from small scale experiments, a full-scale production line based on the method has been built, and successful full-scale trials have been carried out.

- En ny formingsmetode for aluminium til deler i bil er utviklet - En mer material- og energieffektiv produksjonsmetode for produksjon av bildeler i aluminium - Prototyper er utviklet for utvalgte bildeler basert på ny forme-metode - En ferdig full-skala produksjonslinje basert på den nye forme-metoden er bygget, og brukt i forbindelse med testkjøring - Økt kompetanse blant prosjekt-deltagerne i forbindelse med effekt av endret termomekanisk prosess

To meet the overall industrial requirement to be significantly more material- and energy efficient in the production of car components, a new forming technology is proposed, the PressFormHardening (PFH). The innovation in PFH is to simplify tooling and heat treatment techniques for sheet forming of age-hardenable aluminium alloys. Although a rising number of car components are made (normally castings) of aluminium alloys, a car is still essentially a box of steel on wheels. The demand for more aluminium is increasing mainly because of its potential to reduce overall weight. Aluminium alloys are currently used in many components in cars, but still castings dominate the tonnage. The use of formed sheet is limited due to high manufacturing costs that prevent mass production to high volume marked. Increasing the use will require a smarter production process with fewer steps and were all the beneficial properties of aluminium are utilized. Traditionally, forming of aluminium is carried out in cold condition. The formability is then limited, imposing substantial restrictions on the designer. Cold forming also requires a stable, predefined state of the alloy to reduce the variation in geometric tolerances due to spring-back (elastic behaviour). These conditions reduce the possibility to obtain maximum strength during the following ageing heat treatment. PFH is a new process that will make it possible to produce more complicated geometries within narrow geometry tolerances, higher strength, increased ductility and better crash performance. The PFH-method has to our knowledge, not previously been developed for industrialization. The method will thus go beyond the state-of-the-art in the field of sheet forming.