|
| Abstract No.: |
|
Scheduled at:
|
Wednesday, May 04, 2022, Hall D 4:15 PM
Young Professionals Session
|
|
| Title: |
The development of thermal barrier coatings by the bond coat topography functionalization – computational and experimental approach
|
|
| Authors: |
Tomasz Kielczawa* / Wroclaw University of Science and Technology, Poland
Pawel Sokolowski / Wroclaw University of Science and Technology, Polska
Leszek Latka/ Wroclaw University of Science and Technology, Polska
|
|
| Abstract: |
The applicability of Thermal Barrier Coatings (TBCs) depend mainly on their thermophysical properties and thermal cyclic behavior. In this work, the possibility of controlling the thermally sprayed TBC microstructure is investigated, due to its influence on the overall TBC performance. The control was possible primarily by bond coat surface microtexturization prior top coat spraying. Such pretreated bond coats were modeled and parameterized to investigate the influence of the substrate topography on the plasma stream behavior as well as the feedstock particle thermophysical properties and trajectories in the substrate boundary layers. Advanced flow models were introduced to the governing equations to define the plasma generation, turbulent flow, and plasma jet / feedstock particles interaction. For the feedstock phase definition, the Discrete Phase Model (DPM) was used. Tracking of the particles both in the free-jet area and in the microtexturized surface boundary layers were defined by this model. The computational studies were verified with the experimental approach. The feedstock injection and fragmentation was observed with SprayCam shadowgraphy system. Then, the TBCs were sprayed on the microtexturized bond coats with topographies corresponding to the numerical cases and were subjected to microstructural observations and thermal cyclic fatigue testing. The motivation for this study was to model and investigate the influence of the bond coat microtexturization on the behavior of the feedstock particles in the substrate boundary layer. This opens the possibility of better understanding the TBC build-up mechanism and strictly controlling the microstructure of such TBCs.
|
|