Magnesium as a Lightweight Metal Lightweight Cluster Trusts in Magnesium
The latest cluster meeting at the Landshut University of Applied Sciences, hosted by the Automotive Cluster, the New Materials Cluster and the University's Lightweight Cluster, focused entirely on magnesium as a lightweight metal. The speakers showed the lightweight construction potential of magnesium castings and sheet-metal parts.
The speakers from industry and science showed the lightweight construction potential of magnesium castings and sheet-metal parts, which will be increasingly used in multi-material designs in the future. In the field of lightweight construction, metals and magnesium, in addition to aluminium, are an important topic, as Dr. Matthias Konrad, Head of Materials, Bayern Innovativ GmbH, Nuremberg, explained the background to the event. At Landshut University of Applied Sciences, where lightweight construction has been playing an important role since 2001, concentrated on studying, as the University’s President Prof. Dr. Karl Stoffel explained in his welcoming address.
Magnesium is the Most Underrated Lightweight Metal
For Klaus Decking (former Georg Fischer Automotive AG in Schaffhausen, Switzerland), magnesium is "the most underrated material when it comes to lightweight construction". It has great advantages and still has a lot of unlocked potential that needs to be exploited. Production costs for carbon components are about three times higher than those for aluminum or magnesium.
In addition, magnesium requires fewer processing steps. New manufacturing processes such as cast rolling make it possible to produce magnesium more cost-effectively, which means that, in addition to its material properties, magnesium is increasingly being considered by the industry from an economic point of view. There is no lack of technology or material, but of companies that use it.
Christoph Schendera from the European Magnesium Research Association e. V. welcomes an increased use of magnesium, which is the lightest metallic structural material. The reasons for this point of view include its excellent castability, a high strength/weight ratio and thus a high weight-saving potential of approx. 55 % compared to steel and 25 to 40 % compared to aluminium as well as 100 % recyclability and almost unlimited availability. Although the price per ton of magnesium is higher than that of aluminium, it offers a higher potential to save weight.
Flammability and Corrosion of Magnesium are Manageable
On average, about 4 kg of magnesium would be required per vehicle, compared to just under 150 kg of aluminium. The prejudice that magnesium would burn and corrode has an inhibiting effect on its application. He said that both issues could be handled, even though a great deal of know-how and above all long-term experience with different alloys of magnesium would still be needed. He sees additional areas of application for magnesium in the ecologically and economically driven lightweight construction of modern vehicles with a multi-material design. For example, if the doors and tailgates of a vehicle are made of aluminium and magnesium in a mixed construction instead of steel, around half the weight, i. e. around 40 to 50 kg, could be saved.
Magnesium Sheets Must Also Be Ready for Series Production
The promising potential of magnesium as a lightweight material has once again become the focus of attention in automotive engineering, but the topic is not a new one, explains Dr. David Klaumünzer of Volkswagen. The engine block and gearbox housing of the VW Beetle had already consisted of magnesium castings, around 20 kg of magnesium would have been used in every vehicle. Apart from aluminium, components made of magnesium castings are increasingly being used in vehicles today. There would be many more possibilities, but first, magnesium sheets must be fit for use in these areas.
VW is currently developing a promising magnesium wrought alloy that will allow the production of automotive components by hot stamping at relatively low temperatures. The possible uses could be significantly increased, for instance, in the case of external sheet metal and add-on parts. This would unlock the potential magnesium sheets can offer in lightweight construction.
Researchers Model the Material Properties of Magnesium Sheets
The BMBF-funded (German Federal Ministry of Education and Research) project ‘Magfest’ at the Landshut University of Applied Sciences aims to characterize and model the material properties of magnesium sheets to provide the basis for the simulation and design of components. Under the direction of Prof. Otto Huber, of the Competence Center for Lightweight Construction at the Landshut University of Applied Sciences (LLK), an experimental analysis and numerical modelling of the fatigue strength behavior of wrought magnesium alloy sheets was carried out.
Josef Denk from LLK presented an energy-based damage model in the uniaxial range. This model shows very large similarities with experimentally determined results and is therefore suitable as a basis for the life time estimation and the stable design of components. Various alloys produced in the casting or extrusion process were examined. Further research activities for the analysis and modelling of notched and reshaped magnesium sheets are currently being carried out at the LLK in cooperation with the Paris Lodron University of Salzburg (Department of Chemistry and Physics of Materials) as part of the Interreg project Nano-to-Macro.
Optimized Process for Magnesium Casting at BMW
Dr. Andreas Fent from BMW demonstrated the development of an optimized process for magnesium casting, using a magnesium support structure for the dashboard of the new 7-series. This process ranges from the first component design and its optimization, through simulation of the casting tool to the finished casting cell, in which both magnesium and aluminium can be cast. Finally, Anton Schönbauer from the SSD Scientific Solution Division of Olympus Austria GmbH presented the non-destructive analysis of metals using X-ray fluorescence analysis. The devices developed by this company could also be used for magnesium, but require a special setup.
This article was first published by Blechnet.