Testing a new method for characterization and optimization of the adhesion strength of ceramic and metallic coatings
Thermal Barrier Coating
At a glance
- Project leader : Dr. Yasser Safa
- Project team : Scherrer Christof, Thomas Hocker, Arnd Jung, Dirk Penner, Mark Terner
- Project budget : CHF 90'000
- Project status : completed
- Funding partner : Internal
- Project partner : Alstom
- Contact person : Yasser Safa
Description
Ceramic and metallic coatings of components with high performance requirements such as turbine blades are used for protection against wear, corrosion and overheating. Their adhesion under operating conditions plays a central role for the component life. The development of these protective coatings depends strongly on the available methods. While materials analysis techniques such as SEM, EDX, TEM and XRD are now established, adhesion tests are still traditionally performed with "Haftzugversuchen" (adhesion tensile tests), their limitations in terms of accuracy and reliability is well known in professional framework. For this reason, a new method for the characterization and the optimization of the adhesion strength of ceramic and metallic coatings to be set up in the context of this project. Pursuing a combined experimental and numerical approach:
XRD analysis of the residual stresses of coatings
Indentation method for introducing precisely defined crack
initiation in the boundary layer between the adhesive and
coating
Acoustic emission analysis of the initiation and propagation of
delamination of coatings
Numerical analysis of stress distributions, the buckling behavior
and the crack propagation in coatings