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@PHDTHESIS{Joeris:1032300,
author = {Joeris, Jana},
title = {{A}bscheidung kolumnarer {W}ärmedämmschichten mittels
{S}uspensionsplasmaspritzen ({SPS}) und {P}lasma {S}pray –
{P}hysical {V}apor {D}eposition ({PS}-{PVD}) {P}rozesse},
volume = {628},
school = {Bochum University},
type = {Dissertation},
address = {Jülich},
publisher = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
reportid = {FZJ-2024-06139},
isbn = {978-3-95806-752-3},
series = {Reihe Energie $\&$ Umwelt / Energy $\&$ Environment},
pages = {vii, 133},
year = {2024},
note = {Dissertation, Bochum University, 2023},
abstract = {In this work, columnar thermal barrier coatings are
prepared by suspension plasma spraying (SPS) and plasma
spray-physical vapor deposition (PS-PVD) process. For
industrial applications, increasing the lifetime of the
coatings is an important aim. For this purpose, the thermal
expansion coefficient of metal and ceramic is equalized by
introducing an oxide dispersion strengthened (ODS) layer,
which can reduce the radial stresses in the thermal barrier
coating. Furthermore, the service life is extended by
pre-oxidation of the bond coat with formation of an aluminum
oxide layer. At the beginning of the work, the material and
process parameters for the coating processes are evaluated.
The objective is to produce columnar microstructures that
have a high column density. In the SPS process, the
microstructure is significantly affected by the feed rate of
the suspension. Too high feeding rates increases the
porosity of the coating strongly and significantly reduce
the deposition efficiency. Columnar structures are then
difficult to produce. To deposit columnar structures, the
atomization of the suspension and the melting of the
agglomerated particles must be optimized. This is achieved
by optimizing the plasma gas composition and quantity. For
the SPS process, a high column density is achieved when
as.sprayed bondcoats with a high number of roughness peaks
are used, whereas polished surfaces are required for the
PS-PVD process. The evaluated parameters are then used to
coat cylinders and thermal cycle samples of IN738 and
CMSX-4. Thermal cycling samples are used to investigate the
thermal shock resistance of the thermal barrier coatings. In
addition to the microstructure of the topcoat, the
composition of the bondcoats has an impact on their
durability. By using ODS layers, the lifetime of the thermal
barrier coating (TBC) can be improved. Promising results can
be achieved by pre-oxidation of the bondcoats. By
heat-treating the bondcoats before coating the topcoat, a
thermally grown oxide (TGO) layer is formed, which makes it
possible to increase the lifetime of SPS coatings
significantly. This makes it possible for the first time to
produce single-layer SPS coatings that have comparable
lifetimes to other coating processes. The present work was
carried out within the framework of the Collaborative
Research Center SFB/Transregio 103 "From the atom to the
turbine blade".},
cin = {IEK-1},
cid = {I:(DE-Juel1)IEK-1-20101013},
pnm = {1241 - Gas turbines (POF4-124)},
pid = {G:(DE-HGF)POF4-1241},
typ = {PUB:(DE-HGF)3 / PUB:(DE-HGF)11},
doi = {10.34734/FZJ-2024-06139},
url = {https://juser.fz-juelich.de/record/1032300},
}