MFN was able to arrange an interview with Dr.-Ing. Karsten Röttger, CEO, ECOROLL AG Werkzeugtechnik.
(?) MFN: Thank you Dr. Röttger for taking the time to do this interview.
(!) K. R.: Thank you for giving me the chance to talk about something I am so passionate about.
(?) MFN: Before we start to talk about the latest and upcoming innovations in the field of surface treatments, can you first describe what mechanical surface treatments are and what these processes are used for?
(!) K. R.: Sure. Mechanical surface treatments are finishing processes to improve the surface and subsurface properties of metallic parts, such as bearings, shafts or turbine blades. Typically, these processes use the effect of cold working to increase either the surface quality or the mechanical properties; for example, hardness or residual stresses. The most beneficial effect comes from the induced compressive residual stresses, which lead to a significantly higher fatigue life. There are different processes for that, such as roller burnishing, shot peening, deep rolling and machine hammer peening.
(?) MFN: What means significantly higher? Can you give a number for that?
(!) K. R.: I give you an example: We had the task to increase the lifetime of steering knuckles. We changed the material and the geometry to reduce the notch effect. Both increased the lifetime by a factor of 2 or 2.5. So, we applied the ECOROLL process deep rolling on the steering knuckles. With deep rolling, a simple process conducted in the same lathe as the actual machining, we were able to increase the lifetime by a factor of 5. I love this example, because it really highlights the benefits of the deep-rolling process. It is just an incredibly simple but effective process.
(?) MFN: This excellence was honored last year by the industry giant Bosch, when you and your company were awarded as the best supplier in the category of innovation. Congratulations on that. That was certainly a special moment for you?
(!) K. R.: Yes, it was. The whole team worked very hard in past years to support BOSCH with this very effective process. We jointly developed a specialized tool, conducted experiments and improved our own manufacturing processes in this project. It was intense, but now we are very happy and honored to have received this award.
(?) MFN: Being awarded as the most innovative supplier is probably not just because of one project. Innovation must be important for you?
(!) K. R.: I always believed that as a company we have to innovate and create to make a relevant impact in the market. ECOROLL is the market leader and we’d like to stay in this position by creating new tools and innovative processes for our customers. This is what our customers value in our products.
(?) MFN: What are the latest innovations from ECOROLL?
(!) K. R.: Recently, there have been two innovations that I think are worth mentioning. The first is the development of our machine hammer-peening tool “ECOpeen” and the second is the process control “ECOsense”. With ECOpeen we introduced a new process into the ECOROLL tool family. Machine Hammer Peening (short: MHP) is an impact process. This means a hammer tool impacts the surface with very high frequencies, while the tool is moving relative to the surface. Compared to other tools on the market, ECOpeen provides really high impact energy. With our first-generation tool, we hit the surface with up to an impact energy E = 100 mJ, which is about five times higher than our competitors’, and we already have concepts with 700 mJ in the pipeline.
(?) MFN: Why is it necessary to have these high energies?
(!) K. R.: This offers two important benefits: productivity and lifetime. Usually, the feed of these tools depends on the affected surface area in one hit and the overlap of the next hit. So, if you want high feed values for a high productivity, it is necessary to have large tool radii and a high indentation of the tool, and for this, you really need high impact energy. On the other hand, the resulting depth of the compressive residual stresses is also affected by the tool radius and the impact energy. This means we are able to induce residual stresses for example in Inconel in a depth of up to 4mm from the actual surface. Compared to deep rolling, which already induces significant residual stresses, this is another huge improvement.
(?) MFN: And now tell me about the second innovation “ECOsense”?
(!) K. R.: Today we need information and data all over the manufacturing processes. In the past, deep rolling was a very analog process unless you spent a lot of money on a process control system. And even then, you did not get the important information about the crucial process parameter rolling force, and especially for parts with very high safety requirements, it is absolutely important to know the rolling force. Let me tell you why. If you apply a rolling force of 1 kN for one part and 2 kN for a different part for example, both parts really look the same. You cannot see or measure any difference without destroying the part to measure residual stresses. But this difference is important for the lifetime, as one part might have a significantly reduced service life. This is definitely not acceptable in aerospace parts for example; therefore we developed the ECOsense technology. This is a very smart and cost-efficient process control device for mechanical rolling tools.
(?) MFN: What makes this technology so valuable?
(!) K. R.: We included a microcontroller, sensors and data storage into our tools. With the sensors, you can measure the rolling force, store the values for all of your processes, and transfer this data to an easy-to-use application on your smart phone via Bluetooth signal. In the app, you can also include process limits that help to decide if the process was within specifications or not. All this information is summarized in different protocols for each process. From day one of this project, we decided to not just create a digital version of our tools, we wanted to be able to get as much information as possible out of the process and the tools for our customers as well; therefore we invested a huge amount of money in the development of the hardware. And we wanted our customers to switch effortlessly from analog to digital, so you can basically just buy the ECOsense technology and attach it to your existing tool. Of course a little calibration is necessary, but after that you are good to go!
(?) MFN: Have you already received customer feedback? Are they appreciating this solution?
(!) K. R.: Yes, we launched this product in the first half of 2020 and so far, our customers are happy with the product. But they already told us to go on with the development and really include this into a smart factory. We knew this. The smartphone solution is good and we will keep this in our portfolio, but it is only the first step for a digital tool. Integration of machine- and cloud-data are just two important steps for the future. But it was still a good idea to start fast and at low cost for what is now called MVP.
(?) MFN: How do you keep this innovative spirit in your company?
(!) K. R.: We apply a dual approach to the innovation process. We listen very carefully to the needs of your customers, and on the other hand we cooperate really closely with different universities in Germany and all over the world, as for example, the ARTC in Singapore. This allows us to get the newest scientific results about deep rolling, surface modification and digitalization and translate them into tools and processes to fulfil the needs of our customers. We participate in different working groups and organizations like the DGM (German Association for Materials) for example.
(?) MFN: What are the next steps or trends in mechanical surface treatments you have to work on in the future?
(!) K. R.: This is a tricky question. We have a lot of challenges and changes in the die-manufacturing industry. I do not assume we’ll have to deal with a large number of new materials, but with different part geometries. Additive manufacturing will lead to different part design concepts and we’ll have to treat these parts as well, so this requires new solutions. A second area is digitalization, and with ECOsense, we have established a basis on this new ground, but there are so many developments popping up every day. This will be intense to keep track of.
(?) MFN: Thank you very much for your time and good luck for you and the ECOROLL AG.
(!) K. R.: You are welcome. Thank you for having me.
MFN would like to thank Karsten Röttger for this interview!
ECOROLL AG Werkzeugtechnik
Hans-Heinrich-Warnke Str. 8
29227 Celle, Germany