An interview with Professor Dr.-Ing. Roland Wahl, Steinbeis Entrepreneur at the Steinbeis Transfer Center for Laser Processing and Innovative Manufacturing Technology
Precise edges, exact cuts, no chips, no material wear – just some of the advantages offered by laser technology. To find out more, TRANSFER magazine met up with Professor Dr.-Ing. Roland Wahl, a Steinbeis expert from Pforzheim University. One thing Wahl knows for sure is that a slew of exciting developments still lie in wait for us in this area. Indeed, many fields of industry are already reaping the benefits of laser technologies.
Hello Professor Wahl. Your Steinbeis Enterprise works on the development of applications that deliver wear protection. What’s your focus in this area?
Our focus lies in processes that protect the components of our customers from wear through the use of lasers. There are two particularly important types of technology in this area: laser hardening and laser deposition welding. Both fall under the fields we focus on at our Steinbeis Enterprise.
Which services offered by your Steinbeis Enterprise are in particular demand at the moment?
For many years, there’s been particular demand for adding hard metal layers to steel parts using laser deposition welding, and that’s not different at the moment. This is because compared to the conventional application methods used for hard metal coatings, which are based on tungsten inert gas welding (or TIG welding), in many areas of industry – like with the tools that are used in hot forming – we can use this method to improve the service life of parts by a factor of two or three. This is also a big success from an ecological standpoint, which makes us proud. And, of course, there’s the fact that the costs of the laser process are far beyond this factors compared to the TIG process.
Also, there’s been strong demand for laser hardening for at least ten years now wherever there’s a need for hardening, but the process heat shouldn’t cause distortions or reworking of the components.
Thinking about innovative production and innovative materials – how important will laser technology be to this area in the future?
It’s very important already, because of lasers’ ability to exert an extremely intensive and highly targeted influence on components, i.e. actual materials. This importance is set to rise in the coming years, because lots of innovative features offered by new products hinge on innovative material combinations.
To provide just one example of this, although it’s a highly topical example, I’d point to high-performance batteries used in electric vehicles, which for instance require a huge number of vibration-proof electrical connections between aluminum and copper. The conventional approach is to use a welding process based on diffusion principles, but that takes too long and thus makes things too expensive. So the aim is to create alloys that are sufficiently vibration-resistant in the join area using laser beams, which carry out fusion welding much faster because the impact of the heat can be more targeted, and that wasn’t previously possible with conventional fusion welding due to difficult metallurgical factors.
What trends are you currently witnessing in laser material processing?
Many of the trends happening in laser materials processing are initiated by the customer market, which has discovered the advantages of laser processing for certain products and then realigns product designs to match.
A current example of such trends with our partners in the OEM and automotive supply industry is the one I see with new, low-dust brake discs for vehicles. These also involve the use of hard metal weld cladding, even with hard metal mixtures which are easier to process than in areas like the tool industry. This set in as a trend when it was discovered that with these brake disks, there are effective ways to use brake pads and produce significantly fewer fine dust particulates.
I see one extremely interesting new trend coming to laser welding in the not-so-distant future through the use of increasingly high-strength steels, especially in mechanical engineering, process engineering, and the automotive sector. These higher-strength steels – which could also be interesting for electric vehicle drivetrains, for example, because of the higher drive torques – often have to be welded in a preheated state to ensure the material delivers the high level of seam quality required. Not only are laser beams the ideal welding tool, but if you’re clever when it comes to the approach you adopt, they can also be used for such preheating purposes, so I see some highly interesting developments coming our way.
What can small and medium-sized enterprises do to benefit from these trends?
It’s especially important for small and medium-sized companies to make do with the manpower available to them, so they’ll have to focus fully on the sectors they’re operating in. In those areas it more often doesn’t make sense or it’s not even possible to develop new production processes with lasers completely in-house – in your own R&D department. Developing effective processes involves a whole host of different activities, from handling laser beams and other process components, to the metallurgical testing of produced samples and prototypes, and even testing parts on test benches, ideally based on established international standards. So especially with small and medium-sized companies, it often makes sense to team up with an experienced and reliable R&D partner. Fortunately – and of course I wouldn’t want this to sound like self-promotion – we’re that kind of partner.
And the other point is that the smaller the company and the more focused it is within its own sector of industry, the more interesting it can be to have laser work carried out by such a partner in the long term. That’s also something we’ve done, and continue to do; and the closer the level of collaboration, the easier and more successful it will go, even over the course of many years.
Contact
Prof. Dr.-Ing. Roland Wahl (interviewee)
Steinbeis Entrepreneur
Steinbeis Transfer Center Laser Processing and Innovative Manufacturing Technology (Pforzheim)