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@PHDTHESIS{Vorktter:874257,
author = {Vorkötter, Christoph},
title = {{A}luminiumoxiddispersionsverstärkte
{H}aftvermittlermaterialien in {W}ärmedämmschichtsystemen},
volume = {488},
school = {Univ. Bochum},
type = {Dissertation},
address = {Jülich},
publisher = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
reportid = {FZJ-2020-01348},
isbn = {978-3-95806-457-7},
series = {Schriften des Forschungszentrums Jülich Reihe Energie $\&$
Umwelt / Energy $\&$ Environment},
pages = {VIII, 99, XXXIII},
year = {2020},
note = {Dissertation, Univ. Bochum, 2020},
abstract = {Thermal barrier coatings typically consist of a ceramic top
coat on a metallic bondcoat. Used for gas turbine parts, for
example the turbine blade, these coatings can protect the
blade material from the high temperatures of the combustion
gasses, corrosionand oxidation. Besides enhanced top coat
bonding, the bond coat ensures oxidation protection of the
blade material by oxidising itself. In the present thesis
thermally sprayed alumina oxide dispersion strengthened
bondcoat materials were produced for the use in thermal
barrier coatings. High energy milled bond coat materials
were analysed with respect to the material properties and
the behaviour in thermal barrier coatings, which were
manufactured on single crystal superalloys with a common
yttria stabilized zirconia top coat. The bond coats low
porosity was achieved by low pressure plasma spraying. For
the high porosity of the top coat atmospheric plasma
spraying was used. The aging mechanisms of thermal barrier
coatings are influenced by several factors. Main factors are
stresses in the thermal barrier coating. These stresses
arise from the thermal expansion coefficient missmatch
between top coat, bond coat, blade material and the oxide
layer thermally growing on the bond coat. Previous studies
showed a high thermal cycling performance of thermal barrier
coatings with double layered bond coats consisting of 2
$wt.\%$ alumina oxide dispersion strengthened bond coats on
conventional bond coats compared to thermal barrier coatings
with single layered conventional bond coats. The approach of
this thesis is an increased alumina content up to 30 $wt.\%$
in the oxide dispersion strengthened bond coat. The result
is a lower thermal expansion coefficient of the upper bond
coat reducing the stresses in the thermal barrier coating,
which offers a possible increase in thermal barrier coating
thermal cycling performance. The approach was proved for
thermal barrier coatings using $10\%$ alumina in the oxide
dispersion strengthened bond coat. As a result of the lower
oxidation resistance of $30\%$ bond coat material, a further
increase to $30\%$ alumina does not further improve the
thermal cycling performance due to the lower thermal
expansion coefficient. Furthermore thermal barrier coatings
with columnar structured top coats combined with oxide
dispersion strengthened bond coats are promising candidates
for high thermal cycling performances. Wear resistant tests
showed an increased wear resistance especially for $30\%$
aluminia oxide dispersion strengthened bond coat materials.
The research of the present thesis was embedded in the
collaborative research center SFB/Transregio 103 “From
atoms to turbine blades“ focussing on the developmentof
superalloys. Correspondingly single crystal superalloys were
used for the thermal barrier coatings [...]},
cin = {IEK-1},
cid = {I:(DE-Juel1)IEK-1-20101013},
pnm = {113 - Methods and Concepts for Material Development
(POF3-113)},
pid = {G:(DE-HGF)POF3-113},
typ = {PUB:(DE-HGF)3 / PUB:(DE-HGF)11},
url = {https://juser.fz-juelich.de/record/874257},
}