Will the car of the future be made of magnesium?

  • Magnesium door would be half the weight of steel with comparable properties and cost
  • New slide-ground tumbled alloy wheel rim process brings benefits
  • Quick-hardening adhesive allows headlight glass to glued on in a minute

Magnesium instead of steel – this could be an option for lightweight car body parts. A car door made of magnesium is roughly 50 percent lighter.

Researchers in Germany are developing unique lightweight car components. An example is the car door made of magnesium, a development by researchers at the die Fraunhofer Institute for Machine Tools and Forming Technology IWU in Chemnitz, Germany.

The door weighs just around 4.7 kg. By comparison, the version in steel weighs around 10.7 kg.

Of all substances, though, why magnesium?

Magnesium is available in large quantities worldwide. It can be moulded, and for similar structures – a car door, for instance – it has virtually the same properties as steel, and comparable rigidity.

“We have developed specific moulding technologies for wrought magnesium alloys. This makes the lightweight material available for future use in series production of car bodies,” summarises Sören Scheffler, group manager at IWU.

IWU researchers have also developed a slide-ground tumbled alloy wheel rim. In the process of slide-grinding and tumbling, the wheel rim is moved through a fill of abrasive media moving with a particular frequency.

As one would with sand paper, manufacturers begin with coarse abrasive media and replace this with finer and finer abrasives over several steps.

While slide-grinding is a conventional technology, to date it has lacked clear specifications: what frequency must be used to stimulate the abrasive media? How does one move the wheel rim through the process? What geometries and shapes of abrasive media are best suited to the task?

Researchers at the Fraunhofer Institute for Production Systems and Design Technology IPK in Berlin are now investigating the theoretical connections and making a systematic record.

Car manufacturing can also be optimised through the use of new joining processes. Researchers at the Fraunhofer Institute for Manufacturing Technology and Advanced Research IFAM in Bremen have come up with a gluing process that allows for markedly faster production, such as in the glass front of a headlight.

Conventional adhesives need several hours before they are hardened through humidity – and the headlight has to be held in place throughout this period.

IFAM researchers use an adhesive that is also heat-hardening. They heat it locally using a microwave antenna, and within one minute the adhesive has hardened and assembly can continue. The new adhesive is already ready for use in industry.