A vehicle powered exclusively by solar energy? Something that sounds both fascinating and utopian is not a work of science fiction, but already the impressive reality for Team Sonnenwagen. The aim of the project is to survive a rally that runs for more than 3,000 kilometres through the Australian outback. But it takes more than just a soapbox car cobbled together in a garage: a high tech approach is essential. As a gold sponsor for a sustainable project like this, we are obviously happy to bring all our machining know-how to bear, and make skilful use of our tools to shape the durable yet lightweight titanium material.

Team Sonnenwagen Aachen is an Aachen-based student initiative for developing and building solar-powered cars capable of participating in international competitions. Every two years, around 50 students from RWTH Aachen University and FH Aachen University of Applied Sciences develop a new Sonnenwagen solar car. It is powered entirely by solar energy, and the rules dictate that there must be room on the roof of the vehicle for 4 m² of solar panels.

To achieve the greatest possible range, a solar car needs more than just perfect aerodynamics; it must also be constructed with lightweight materials. This time, the students were able to reduce the weight compared to its predecessor model by more than 16%. This is the result of using advanced materials such as titanium, and innovative production methods. In the CERATIZIT Tech Centre, the titanium and aluminium machining expertise contributed by our CERATIZIT experts proved particularly useful for creating components for the wheel suspension, including wheel carrier, wheel hub and axles, as well as for the balance bar system within the braking system.

The distinguishing feature of the Covestro Adelie – the name given to the new solar-powered vehicle – is its exceptionally low drag. The design had to take the following into consideration: minimal space for installation, adequate safety for the driver and lightweight construction. A particular advantage of using the high-strength titanium alloy TiAl₆V₄ is that the design components can now be far more compact, and weigh noticeably less. But the combination of ductility and great tensile strength makes titanium much more difficult to machine than steel or other materials. So the choice of tools was particularly important, and applying the right parameters was also key to the success of the concept.

Sharp cutting edges and the correct cutting speeds are the best recipe against the dreaded work hardening when machining titanium. This was why the specifically adapted WTX-Ti high-performance drills made their appearance, and the MonsterMill TCR solid carbide end mill was equally impressive – not least thanks to its DRAGONSKIN coating. This extremely wear-resistant coating technology on our high-performance tools also withstands the high temperatures present when machining titanium. The SilverLine solid carbide end mills also delivered excellent performance due to the higher cutting speeds made possible by advanced geometries and a DRAGONSKIN coating

The versatile EcoCut series with the relevant grooving and indexable inserts was mainly used for turning operations, as it could be used not only for drilling, boring and face turning, but also for external machining – without needing annoying and time-consuming tool changes. Essential for machining the titanium were the MaxiLock N-DC tool holders with DirectCooling (DC), which could be used for targeted coolant application to the cutting edge – a huge advantage at extremely high process temperatures.

The international CERATIZIT team had an extensive portfolio of tools to fall back on, ensuring that a suitable machining solution was always at hand for what were sometimes highly complex components: from adapter and holder to the suitable indexable insert – everything between chip and spindle!

The Bridgestone World Solar Challenge is the top event for solar-powered vehicles, and thus also for Team Sonnenwagen Aachen. The aim of the event is to promote and publicise solar mobility research and development. Fifty teams from internationally renowned universities chase across the Australian outback from Darwin to Adelaide in a race covering 3,022 kilometres. Those involved include Cambridge University, TU Delft, Stanford University and the MIT. Outstanding development work that makes optimum use of the available solar energy is pivotal to success. Incidentally, the Bridgestone World Solar Challenge is said to be the most difficult solar-powered car race in the world.

Something that sounds too good to be true, and even works under the toughest conditions: a vehicle that is not only driven by the power of the sun, but is also fit for a rally of more than 3,000 kilometres on the other side of the world. A project with sustainability value! JUST OUR THING!