From cars to aeroplane engines: turning, drilling and milling components require cutting tools that have to withstand a lot.This is why they are specially coated.Nina Schalk knows how.
Nina Schalk from the University of Leoben wants to know exactly: Using various methods and devices, she looks as closely as possible into the wafer-thin coatings for metal tools: how do the different elements arrange themselves, do they form large or small crystals, how do they react to heat or oxygen? And what does this mean for hardness, fracture toughness and durability? These findings from basic research are very valuable for the company partner CERATIZIT Austria Gesellschaft m.b.H. - they are the starting point for improving existing tools and developing new ones for metalworking.
Martin Gerzabek, President of the CDG: ‘Coating tools - that may sound boring to some.But Nina Schalk, her team and her partner CERATIZIT see it differently.Their research is not only incredibly exciting, it also leads to more durable, resource-efficient products, for example for the automotive industry, turbines for energy generation or aircraft engines.Austria needs knowledge, technical expertise and innovative strength to remain fit for the future.Nina Schalk is an excellent example of how CD Laboratories are one of the places where precisely this is lived and passed on.A well-deserved award winner, to whom I also extend my warmest congratulations."
Wilfried Eichlseder, Rector of Montanuniversität Leoben, explains the importance of CD Laboratories for his university: "CD Laboratories provide an ideal basis for scientists who are establishing their own field of research.On the one hand, the academic environment in which the CD Laboratory is located provides the basis for scientific work, and on the other hand, there is a close connection to industrial partners who contribute their expertise and form the bridge from scientific findings to implementation in product development.Eight CD Laboratories are currently active at the University of Leoben.I wish all the heads and employees many scientific findings and, above all, joy in their work!May the partners from industry incorporate as many of these findings as possible into successful products!
Wafer-thin layers, state-of-the-art equipment, new methods
Even the production of the coatings is an exciting process: ‘pre-material’, the material that is to form the coating, is vaporised in a deposition chamber - and is then deposited on the workpiece to be coated. Depending on the elements and composition of the pre-material, and depending on the pressure, temperature, gases supplied, etc., different coatings are created.
These coatings are around three to twenty micrometres thick. For comparison: a human hair has a diameter of around 50 micrometres. With the right instruments, however, entire landscapes of elements, phases, layers and crystals become visible. For example, the phases can be crystalline or amorphous, they can lie on top of each other in layers or one can enclose the other and form a nanocomposite, and so on. This is the world that Nina Schalk and her team are researching and describing - and linking it to the properties of the material: hardness, toughness, temperature resistance, oxidation and much more.
Whether scanning electron microscope, transmission electron microscope, X-ray diffractometer or synchotron particle accelerator: many of the CD Laboratory's methods involve bombarding the material with electrons or X-rays and drawing conclusions about the smallest structures of the material from the reactions. Prizewinner Schalk highlights the atom probe as a particularly exciting example - after all, the University of Leoben is home to the only two atom probes in Austria: prepared thin tips of a few hundred nanometres are vaporised atom by atom - the vaporised atoms land on a position-sensitive detector that makes it possible to deduce which atom was where. Parts of the coating can therefore actually be visualised at an almost atomic level. Of course, all these devices do not work by themselves for this particular application: a large part of the research is method development.
Successes and results
Innovation beyond the state of the art: Until a few years ago, new coatings were developed by trial and error. The new methods now make it possible to understand why some materials and methods are more suitable than others. On this basis, the company can now develop and test proposals for even better materials.
Dragonskin: Based on the results of these investigations, CERATIZIT has developed new coated carbide grades for turning steel, which were successfully launched on the market in January 2022 as so-called Dragonskin coatings. These have a higher durability and also have an indicator layer that recognises heavy wear and the approaching end of the tool's service life in good time. The tool is therefore replaced at exactly the right time - not too early and not too late, another contribution to conserving resources.
Sustainability: When using coated tools, it often gets very hot, so coolants and lubricants are used, which are often harmful to the environment - better coatings can significantly reduce the use of these chemicals.
Circular economy: Greater knowledge makes it possible, for example, to incorporate fewer different elements into the coatings than was previously the case - because there is a better understanding of which properties can be achieved and how. On the one hand, this reduces dependence on critical elements such as tantalum; on the other hand, ‘pure’ materials are also easier to recycle - an important prerequisite for the circular economy.
