Extremely thin ceramic coatings can completely change the properties of technical components. Coatings are used, for example, to increase the resistance of metals to heat or corrosion. Coating processes play a role for large turbine blades as well as for extremely stressed tools in production technology. TU Wien (Vienna) has now investigated what determines the stability of such coatings. And the results, some of which were obtained at the DESY synchrotron in Hamburg, are quite surprising: the ceramic layers break down in a completely different way than metals. Material fatigue hardly plays a role; the decisive factor is the intensity of extreme load peaks (so called stress intensity factor). This finding will change the method used to measure and further improve the resistance of thin films in the future.
