% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@PHDTHESIS{Pecanac:133741,
author = {Pecanac, Goran},
title = {{T}hermo-mechanical {I}nvestigations and {P}redictions for
{O}xygen {T}ransport {M}embrane {M}aterials},
volume = {178},
school = {RWTH Aachen},
type = {Dr.},
address = {Jülich},
publisher = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
reportid = {FZJ-2013-02140},
isbn = {978-3-89336-678-5},
series = {Schriften des Forschungszentrums Jülich Reihe Energie $\&$
Umwelt / Energy $\&$ Environment},
pages = {143 S.},
year = {2013},
note = {RWTH Aachen, Diss., 2013},
abstract = {One of the most efficient ways to realize an Oxy-fuel
process is the utilization of ceramic oxygen transport
membranes (OTMs) for air separation, since this process
provides a significantly lower efficiency loss compared to
conventional cryogenic separation technologies. Driven by
the difference in oxygen partial pressure, the oxygen
transport takes place via oxygen vacancies in the crystal
lattice of the membrane. Thin membrane layers supported by a
porous substrate are considered as the most efficient design
solution for such air separation units. The porous substrate
should provide mechanical stability of the entire membrane
structure. The operational temperatures are rather high,
since the release of oxygen atoms from the lattice at
elevated temperatures aids the transport processes. Due to
their favorable permeation properties, which are an
essential functional prerequisite, several materials were
suggested as promising membrane and substrate materials,
namely:
Ba$_{0.5}$Sr$_{0.5}$Co$_{0.8}$Fe$_{0.2}$O$_{3-\delta}$,
La$_{0.58}$Sr$_{0.4}$Co$_{0.2}$Fe$_{0.8}$O$_{3-\delta}$,
Ce$_{0.9}$Gd$_{0.1}$O$_{1.95-\delta}$ and as alternative
substrate material, the novel Fe21Cr7Al1Mo0.5Y alloy. The
current study aims at the thermo-mechanical characterization
and comparison of those materials. Fundamental mechanical
characteristics such as elastic behavior and fracture
properties were evaluated to warrant the long-term
functionality of these materials. However, the long-term
reliability of the component does not only depend on its
initial strength, but also on strength degradation effects.
In particular, the sensitivity to environmentally enhanced
crack propagation at subcritical stress levels was assessed
and also used as a basis for a strength–probability–time
lifetime prediction. Creep behavior and time to rupture were
characterized, since at operation relevant (elevated)
temperatures long-term failure may occur due to creep
damage. The mechanical limit of the thin membrane layer and
its effect on the stability of the substrate material was
also addressed. Complementary numerical simulations were
carried out to permit an assessment of the experimentally
obtained mechanical characteristics since standard
analytical relationships (ASTM C 1499) are limited to flat
mono-layer specimens. The mainly experimentally based work
was additionally supported by numerical simulations to
assess the effects of the final membrane´s geometrical
arrangement (i.e. tubular and planar) and thickness ratios
of particular layers, in order to optimize the membrane
design.},
keywords = {Dissertation (GND)},
cin = {IEK-2},
cid = {I:(DE-Juel1)IEK-2-20101013},
pnm = {122 - Power Plants (POF2-122)},
pid = {G:(DE-HGF)POF2-122},
typ = {PUB:(DE-HGF)11},
url = {https://juser.fz-juelich.de/record/133741},
}