Duration: 01.05.2021 – 31.10.2023

Research institutions:
Darmstadt University of Technology, State Materials Testing Institute Darmstadt

Within the planned research project, the fatigue loading is to be investigated with regard to the adhesion properties.
functional coatings can be investigated over the entire surface. For this purpose, in consultation with the industry
Application-relevant PVD coating systems (DLC, t aC, a C:H:Me) selected and samples or component sections
coated or made available.
The necessary fatigue loading is to be achieved by acoustic cavitation using ultrasonic coupling transducers.
(sonotrode) can be generated. The standard set by ASTM International (American Society for Testing and Materials) is the
Standard ASTM G32-16 gives a general test specification for tests on the ultrasonic coupling transducer,
which is to be modified and further developed in the project. Here, a variation of the test parameters takes place
(frequency, amplitude, test duration, medium, etc.) with the aid of high-speed camera recordings, in order to
to be able to evaluate the resulting stress in relation to the input variables in a spatially resolved manner.
Based on the results, a comprehensive evaluation of the two-dimensional adhesion properties of the application-relevant
coatings and the suitability of the ultrasonic coupling oscillator method. The targeted
Parameter variations and the evaluation of the resulting interactions as a result of the changed
stress combination form the basis of the qualifying further development of the cavitation examination.
The influence of the microstructure (e.g. columnar, amorphous structures, multilayer layers), as well as the possible forming
Crack growth within the coating is the focus of the mechanistic description. The sonotrodes of the
The ultrasonic coupling transducer is also to be adapted to specifically influence cavitation, in order to test the
on simply contoured and curved functional surfaces for possible prenormative research.