German team experiment proved: green light laser automotive electronic welding can save a lot of raw materials

A collaborative team of researchers in Germany has announced an advance that, together, has provided the most detailed insight yet into the laser welding process. The joint team demonstrated clearly for the first time that raw materials could be saved when welding high-performance electronics by using lasers with green wavelengths.

The team included the results of a survey carried out by TRUMPF, Germany's Fraunhofer ILT and DESY, a large particle physics research institute owned by the Helmholtz Association. Every electric vehicle is equipped with high-performance electronics as a key technology that ensures optimal performance of batteries and motors.

These companies and institutions are working together to develop laser welding processes for electric vehicles, each contributing their deep expertise in X-ray, laser sources and welding processes. They found that when the green wavelength laser was used, the scrap rate was much lower than other laser welding processes, resulting in significant savings in raw materials for automakers and benefits for more sustainable manufacturing.

They are taking high-speed images at a rate of several thousand to ten thousand frames per second, hoping to use particle accelerator X-rays to study what makes the copper weld different.

Marc Hummel, a scientist at Fraunhofer ILT, noted that a stable welding process is important because electric car manufacturers typically need to complete billions of high-quality connections. In the future, TRUMPF and Fraunhofer ILT plan to expand their research into other areas, such as 3D printing, laser cutting and ultra-short pulse laser drilling, and to include other industry partners in the collaboration.

Using green wavelength laser, reject rate is lower

In the process of electric vehicle manufacturing, laser technology presents a very big challenge. Copper is the most important material for building the core components of electric cars. The non-ferrous metal absorbs only about 5% of laser radiation in the near infrared (NIR) range and conducts heat very well. Unfortunately, both of these properties can cause considerable problems when welding. As a result, these processes often require close follow-up inspections.

In addition to near-infrared lasers, Tongkuai also has green wavelength lasers in its product line. Mauritz Mοller, sector Manager, outro, pointed out: "Lasers with green wavelengths are the solution to this problem. In fact, you can weld copper better using these lasers."

Copper absorbs green wavelengths much better than infrared. Because the material reaches its melting temperature faster, the welding process also starts faster and requires less laser power. Finally, a more stable welding process also leads to a lower rejection rate, contributing to more sustainable manufacturing.

Particle accelerator experiment

To study the welding process in detail, experts from the Fraunhofer Institute for Industrial Technology in Germany, in collaboration with the Institute of Laser Technology at RWTH Aachen University in Germany, used DESY's PETRA III X-ray source at the experimental facility at the Helmholtz Center in Germany.

Marc Hummel explains, "The traditional approach is really just to see the electromagnetic emission of the plasma. With DESY's radiation, not only can we see the melting inside, but we can even see the melting dynamic in real time."

To this end, the team from Fraunhofer ILT and Tompf studied the laser welding process of DESY using two different laser systems (near infrared laser and green wavelength laser). Mauritz Mοller said, "For us, this is a good opportunity to study the welding process for industrial parts. For example, how splatters and pores form, and how the heat from the welding process affects sensitive parts like electronic parts."

Source: OFweek