The researchers used particle accelerators to prove that green laser production is more sustainable

The collaboration between TRUMPF, Fraunhofer ILT and DESY provides the most detailed insight into the laser welding process to date, thanks to particle accelerator // Fraunhofer expert Marc Hummel: "For the first time, we have now been able to clearly demonstrate that raw materials can be saved when welding high-performance electronics using lasers with green wavelengths.

Welding high performance electronic products can save a lot of raw materials. This is the result of a study conducted by the German electron synchrotron DESY at the Helmholtz Institute in Hamburg. High-performance electronics are present in every electric vehicle as a key technology to ensure optimal performance of batteries and motors. The Hamburg-based researchers worked with the high-tech company TRUMPF and the Fraunhofer Institute for Laser Technology ILT on the laser welding process used to build electric cars. TRUMPF, Fraunhofer ILT, DESY and Helmholtz-Zentrum Hereon each contribute a high degree of expertise in X-ray, laser sources and welding processes. For the first time, this led to insights invisible to the naked eye or even a microscope. Results: When using green wavelength lasers, there is much less waste compared to other laser welding processes. Carmakers save on raw materials, which helps to achieve more sustainable production.

Particle accelerators provide detailed insight

For their investigation, the project partners used bright X-rays from a particle accelerator in the Hereon experimental facility to take high-speed images of thousands to 10,000 images per second. "With the help of particle accelerator research, we want to know what the exact differences are in copper welding. "A stable welding process is important because electric vehicle manufacturers must weld billions of joints of the highest quality," said Marc Hummel, scientist at Fraunhofer ILT. In the future, TRUMPF and Fraunhofer ILT hope to expand their research into other areas, such as 3D printing, laser cutting and drilling with laser beams from ultra-short pulsed lasers, and attract other industry partners to join them.

Electric cars: Green wavelength

Electric vehicles pose a major challenge to laser technology. Copper is the most important material in the production of core components for electric cars. The non-ferrous metal absorbs only about 5% of laser radiation in the near infrared (NIR) range and dissipates heat very well. Both can cause major problems during welding. So these processes are being tested. In addition to near-infrared lasers, Trumpf also offers green wavelength lasers in its range. "The green-wavelength laser is the solution. In fact, these lasers can weld copper better, "said Mauritz Moller, automotive industry manager at Trumpf. Copper absorbs green wavelengths much better than infrared. Because the material thus reaches its melting temperature more quickly, the welding process also starts faster and requires less laser power. "A more stable welding process means less waste and therefore more sustainability, which is a major issue for electric vehicles," says Mauritz Moller.

Electric cars: Green wavelength

Electric vehicles pose a major challenge to laser technology. Copper is the most important material in the production of core components for electric cars. The non-ferrous metal absorbs only about 5% of laser radiation in the near infrared (NIR) range and dissipates heat very well. Both can cause major problems during welding. So these processes are being tested. In addition to near-infrared lasers, Trumpf also offers green wavelength lasers in its range. "The green-wavelength laser is the solution. In fact, these lasers can weld copper better, "said Mauritz Moller, automotive industry manager at Trumpf. Copper absorbs green wavelengths much better than infrared. Because the material thus reaches its melting temperature more quickly, the welding process also starts faster and requires less laser power. "A more stable welding process means less waste and therefore more sustainability, which is a major issue for electric vehicles," says Mauritz Moller.

Experiments in particle accelerators

In order to carry out a detailed study of the welding process, experts from the Fraunhofer ILT, in collaboration with the Chair of the LLT for Laser Technology at RWTH Aachen University, used DESY's X-ray source PETRA III in an experimental facility at the Helmholtz Central Laboratory. "Traditional methods actually only see electromagnetic EMI. From the separation of plasma. With DESY's radiation, we can not only look inside the melt, but even visualize the melting dynamics, "explains Marc Hummel.

To this end, Fraunhofer ILT and the TRUMPF team from DESY investigated the laser welding process of two different laser systems: the near-infrared laser and the green wavelength laser. "This is a great opportunity for us to study the welding process for industrial parts. For example, how spatter and pores are created, and how the heat generated during welding affects sensitive components such as electronic components, "says Mauritz Moller.

Source: Laser Net