FH Dortmund designs aluminum wheels more ecologically and energy-efficiently

A research team at the Dortmund University of Applied Sciences and Arts (FH Dortmund) aims to improve the CO₂ footprint of aluminum wheels for motor vehicles as part of the “SUPA-Wheel” project, together with other project partners. The scientists are working to reduce carbon dioxide emissions throughout the entire production and usage chain of aluminum wheels. In addition to using recycled aluminum, they are also improving the wheel design to further reduce energy consumption during operation. It should also become cheaper.

Anyone who values their image drives aluminum wheels on their car. They are lighter, thus reducing energy consumption while driving, and look more stylish than steel wheels. However, aluminum wheels have a significant disadvantage: their production exclusively uses new aluminum, which is manufactured with a high CO₂ expenditure. The reason: only aluminum with a high degree of purity can be used to produce lightweight, strong, and corrosion-free aluminum wheels, which consist of an alloy of aluminum and other materials. Silicon, iron, zinc, copper, magnesium, and manganese are used.

However, the use of recycled aluminum, which could improve the ecological balance, affects the properties of an aluminum wheel because it also contains other elements. The strength, in particular, can be negatively affected by this.

Finding the right alloy

The researchers at FH Dortmund are therefore first investigating which alloys are suitable for creating an aluminum wheel that can meet the safety requirements of the automotive industry. A total of 300 samples will be evaluated for this purpose. In addition, the researchers are creating a model with which they can predict the properties of alloys and the effects of inclusions of other elements in recycled aluminum. This is because the scientists absolutely want to use recycled aluminum, as it has a “ten times better CO₂ footprint than new aluminum.”

Currently, however, it is only possible to use 30 percent recycled aluminum in an aluminum wheel. “The separation and sorting process is complex, and so far only 30 percent recycled aluminum can be guaranteed as a stable supply quantity,” explains Jakob Nowak, a research assistant in the Mechanical Engineering department at FH Dortmund.

Design optimizations

To further improve the CO₂ footprint of the “SUPA-Wheel,” the researchers are focusing on design improvements. This includes, for example, achieving higher strength in the aluminum alloy to make the wheel lighter with the same stability using less material. The rotating mass is thus lower, and the energy required to move it decreases.

In addition, the researchers are working on aerodynamics. Inserts, plastic covers clamped into the wheel, are intended to improve it, thereby saving fuel or electricity. However, the scientists must first find the right plastic for this. Biogenic plastics are used here, as they are sustainable and can be disposed of more easily than, for example, glass fiber-reinforced plastics. However, the biogenic variants must also withstand high temperatures that can occur near the brake disc.

The “SUPA-Wheel” project will run until mid-2026. Project partners include Borbet GmbH, Trimet Aluminium SE, Jordan Spritzgusstechnik, and Fraunhofer IGCV. The researchers' goal is clear: they want to develop an aluminum wheel that is produced with reduced CO₂ emissions, is cost-effective, and stylish at the same time. It should also sell well on the market.

(olb)