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W. Seidl, M. Bartosik, H. Bolvardi, S. Kolozsvári, P.H. Mayrhofer:
"Stress-Design in TiAlTaN/AlCrN Multilayer Coatings";
Talk: Stress 2016, Chicago; 2016-10-02 - 2016-10-05; in: "Stress Evolution in Thin Films and Coatings: From Fundamental Understanding to Control", (2016), 20.

The build-up of residual stresses in physical vapour deposited coatings is a major concern for application oriented coating development, because they are a main reason for delamination and formation of cracks. Furthermore, residual stresses, which scale up as thickness increases, impedes the growth of thick coating. With increasing stresses, the interface region is increasingly stressed and weakened, promoting delamination and buckling effects. Therefore, the possibility to predict the amount of stresses in a coating and, subsequently, the purposeful manipulation of the residual stress state is of exceptional importance.
In this work, we are analysing the properties of two monolithic systems and the influence of bias potential and other coating parameters on the residual stress state of the coatings. These coatings are TiAlTaN and AlCrN, which are well known for their thermos-mechanical properties and their oxidation resistance, respectively. With this knowledge, various possibilities to combine the monolithic TiAlTaN and AlCrN in multilayer arrangements are investigated. These multilayer arrangements differ regarding their bilayer period, the frequency and manner of bias changes during the coating process, substrate rotation, and the positioning of the used targets. The combination and variation of these parameters allows to adjust the stress states in the multilayer coatings.
The individual coatings and multilayers are additionally investigated with respect to growth morphology (by cross sectional scanning electron microscopy and transmission electron microscopy), hardness and indentation moduli (by nanoindentation), structure and crystallographic phases (by X-ray diffraction).