28 Jun 2023
Industrial laser vendors, machine tool firms, and battery makers discuss the latest progress in Munich.
by Mike Hatcher in Munich
Applications of laser materials processing in automotive manufacturing is one of the oldest themes in the 50-year history of LASER World of Photonics, and that remains the case today, with an inevitable focus on electric vehicle (EV) components.
In a series of talks from players up and down the supply chain, the spotlight fell on welding - and moves to automate the welding process across dozens of individual processing steps needed to produce EV batteries, fuel cells, and electric motors.
Trumpf’s dual optics
First, the laser companies: Trumpf showcased its latest development, a dual optics system said to reduce automated welding cycle times by as much as 30 per cent.
The German laser and machine tool provider highlighted its potential in the production of copper hairpins - key components in electric motors - as well as larger EV elements.
Its “Dual PFO” offers twice the working field of a normal system, making it particularly suitable for processing large components.
“Users can weld these with the Dual PFO without moving the workpiece or the focusing optics themselves,” stated Trumpf, with its automotive industry manager Matthias Beranek adding: “The system is versatile and is also suitable for other large components, such as batteries.”
Welding the hairpins of electric motors must always be of consistently high quality, says Trumpf, and since these components are long and narrow in shape, it is considered to be a very demanding process.
“To achieve high quality, a PFO always measures the position of the component first, before the welding process begins,” explains the firm. “Unlike a normal PFO, the Dual PFO measures and welds in parallel.”
Beranek says that this means users save time and money, while the approach is also compatible with AI-based monitoring through image processing - another strong theme at this year’s event.
Deep copper welds
In a technical forum on the trade show floor confidently entitled “No e-mobility without lasers”, rival laser maker Coherent reported its latest progress in deep copper welding - partly thanks to the capabilities of a low-magnification addition to its “HIGHMOTION 2D” range of laser processing heads.
Aimed at battery busbar and motor hairpin component welding for EVs, and compatible with an 8 kW laser, the update enables deep copper welds of more than 3 mm over a large work area of up to 100 x 140 mm, with virtually no spatter.
Among the other major laser providers, fiber specialist IPG Photonics introduced new adjustable mode beam (AMB) sources said to enable higher-precision, and higher-quality processing for EV applications.
“AMB lasers are being implemented globally in increasing numbers due to their performance, productivity and reduction of defects,” IPG announced.
“Many essential EV manufacturing processes rely on AMB lasers, which have become the technology of choice for high-speed welding of cells to busbars for all battery types, cap-to-can joining, and thin, dissimilar metals welding as just a few of the many examples benefiting from this advanced laser technology.”
Supply chain rises to welding challenges
But the laser companies are only one part of the ecosystem: the e-mobility forum featured speakers representing several levels of the EV supply chain, who outlined the kind of challenges that they have been working to overcome.
Among those were Thomas Blum from machine tool vendor Weil Technology, who discussed the difficulty of welding fuel cell stacks that can feature as many as 4000 individual components.
“Every single unit has to be perfect,” Blum said, adding that ensuring a gas-sealed join between two half-shells was a major challenge, and demanded very high control of the welding process.
Also speaking was Dennis Frisorger from Manz, a leading supplier of production equipment used to make lithium-ion battery cells and modules in volume.
Frisorger highlighted no fewer than 23 different laser welding applications required in EV production, from joining single battery cells, to full battery modules, inverters, power electronics, and the electric powertrain.
Manz has now implemented four different laser approaches to joining lithium ion cells, with 16 kilowatt average power, nanosecond-pulsed, fiber laser, and green sources all featuring for specific welding step requirements.
“I can totally confirm that there will be no e-mobility without lasers,” Frisorger told the forum attendees.