Following the ceremony, with which Joanneum Research wanted to draw attention to over 30 years of cutting-edge research at the Styrian site in Niklasdorf, a scientific seminar was held on the topic of laser production technologies.
Michael Zäh, Professor at the Technical University of Munich, and Tim Hesse from Trumpf Maschinen Deutschland were invited as keynote speakers. In addition, experts from the Joanneum Research Materials Institute gave an up-to-date overview of the group's current research areas.
The presentations
During laboratory tours, the participants were able to gain an insight into the process and plant technology of the Institute Materials"The laser - how refined light enriches production technology" - Prof. Dr.-Ing Michael Zäh, Institute for Machine Tools and Industrial Management (iwb) at the Technical University of Munich, briefly outlined the history of laser development and presented the functional principle of the laser. He then demonstrated the wide range of possibilities in production technology, including laser beam welding and cutting, thermal joining with laser-based surface pre-treatment and laser cladding in additive manufacturing. These manufacturing processes are increasingly supported by artificial intelligence, with optical coherence tomography being used for quality assurance, among other things. The laser is also responsible for many work steps in the production of lithium-ion batteries, e.g. for joining electrode foils, welding cell housings or the external contacting of battery cells.
In the following paper, Dr. Tim Hesse from Trumpf Laser und Systemtechnik GmbH provided information on "Milestones in laser technology and the outlook". Even today,CO2 lasers are still an indispensable tool for cutting and welding. The 10.6 µm wavelength was the benchmark here for decades. Today,CO2 lasers are experiencing a renaissance in the generation of 13.5 nm secondary light (EUV) for wafer lithography. The development continued with solid-state lasers (rod, disk and fiber lasers), which are increasingly achieving higher beam quality and thus very good focusability. In battery production for electromobility, an Eldorado for laser processes, green lasers with shorter wavelengths (higher absorption) are now used for processing copper materials, among other things. The relatively new ultrashort pulse lasers (USP lasers) are also becoming increasingly interesting for many applications, as they can be used to process transparent materials such as glass with high precision. In an outlook on the future of laser technology, the speaker emphasized that productivity, quality and application diversity will continue to increase, with the possibilities for beam shaping playing an important role. Essential degrees of freedom such as intensity, wavelength, polarization and coherence have not yet been used or have hardly been used at all.
"30 years of laser welding at Joanneum Research" - Raimund Krenn, Institute Materials, presented the development and optimization of process and system technology in the field of laser welding on the basis of several projects and applications. In addition to theCO2 laser, solid-state lasers were also purchased and used. The range of projects successfully processed with this equipment ranged from transmission parts and bumpers to continuous strips and ongoing work for electromobility. Services are also offered, with small quantities in some cases even being produced entirely at the institute.
Dr. Richard Görgl, also from the Institute Materials, provided information on the topic of "Laser alloying and 2D/3D laser cladding". He explained the principles of the two processes and then went into specific applications. He presented 3D laser deposition welding (generative manufacturing) using Siemens NX in detail. The technology can be described as state-of-the-art today, although a certain amount of experience is required for its "error-free" application. Since the specific welding parameters and the selected welding strategy influence the result, especially the final geometry, important parameters such as laser power and focusing, traversing speed, powder feed rate or track distance must be optimized. The necessary NC programs are very extensive, as easily programmable geometries are also generated as "point clouds".
Benjamin Meier from the Material Institute spoke about "Metal 3D printing in the powder bed". He presented the 3D Aero TiP project, which aims to develop topologically optimized structural components for aviation made from the titanium alloy Ti6Al4V Grade 5 using the L-PBF process. The L-PBF (Laser Powder Bed Fusion) process enables the production of components with different geometries simultaneously within a single process. In order to achieve optimum component properties (maximum material density, low warpage, minimum surface roughness), the powder quality is of great importance, as is the reusability of the powder from an economic point of view. Previous work has shown that the static mechanical properties achieved are satisfactory, but that the fatigue behavior is still in the critical range.
"Digitalizing and Greening of laser manufacturing process" - This was the topic with which PhD Vojislav Petrovic Filipovic, Institute Materials, concluded the workshop. He pointed out that laser technologies are already fully digitalized. Their environmental friendliness is also good compared to other processes, but there is still potential for optimization. For example, the energy consumption (socket efficiency) of solid-state lasers could be increased from an initial 1% to 50%. This also means less cooling water or the elimination of complex cooling systems. Much has already been achieved here, but there is still potential for optimization.
The laboratory tour
As part of the ceremony and the scientific seminar, participants had the opportunity to visit the laboratories of the Laser and Plasma Technologies research group at the Joanneum Research Institute Materials. The laboratory is well equipped with laser and plasma systems for material processing and the functionalization and coating of surfaces. In the focus area of plasma surface technologies, low-pressure processes such as PVD and PACVD are available for research and development work and in some cases also for services. 3D printing and the subsequent treatment or coating of surfaces is also becoming increasingly interesting for medical technology (antibacterial coatings, barrier layers for implantable electronic actuators and sensors). A relatively new field of research is plasma coating at atmospheric pressure, which offers various advantages compared to low-pressure treatment and can be used, for example, to clean or activate temperature-sensitive materials. The elimination of complex and expensive vacuum systems and the possibility of integrating the processes into existing production lines are further advantages of these technologies.
All photos: Armin Russold
