% 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{Toscano:2198,
      author       = {Toscano, Juan},
      title        = {{I}nfluence of {C}omposition and {P}rocessing on the
                      {O}xidation {B}ehviour of {MC}r{A}l{Y} {C}oatings for {TBC}
                      {A}pplications},
      volume       = {28},
      issn         = {1866-1793},
      school       = {RWTH Aachen},
      type         = {Dr. (Univ.)},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
      reportid     = {PreJuSER-2198},
      isbn         = {978-3-89336-556-2},
      series       = {Schriften des Forschungszentrums Jülich : Energie $\&$
                      Umwelt / Energy $\&$ Environment},
      pages        = {168 S.},
      year         = {2008},
      note         = {Record converted from VDB: 12.11.2012; Aachen, RWTH, Diss.,
                      2008},
      abstract     = {The adherence of the thermally grown oxide (TGO) to the
                      bond coat is recognized to be crucial for the lifetime of
                      thermal barrier coatings (TBC) in aircraft engine and gas
                      turbine blades. The stability of the system has to be
                      guaranteed over extended service times (around 25000h) at
                      high operation temperatures. With this aim, it is necessary
                      that the TGO is slowgrowing and adherent. This work studies
                      the influence of different parameters in the oxidation
                      behavior and scale adherence on MCrAlY-bond coats. For this
                      purpose, three MCrAlY-coatings were selected and subjected
                      to oxidation tests at high temperature in the form of TBC
                      systems, overlay coatings and free-standing coatings. The
                      first part of the work treats the influence of the chemical
                      composition on the oxidation behavior of the bond coat. The
                      second part investigates the influence of non
                      material-dependent parameters: starting with geometrical
                      parameters (surface roughness and coating thickness) and
                      followed by pretreatment/ processing parameters (surface
                      processing sequence, heat treatment parameters and amount of
                      O-impurities). Finally, the work deals with the possibility
                      of defining a critical TGO thickness to failure in EB-PVD
                      TBC systems. The results demonstrate that not only the
                      chemical composition of a MCrAlY-coating but also those
                      geometrical and processing parameters selected can have an
                      influence on its oxidation behavior and scale adherence. The
                      studied Co-base coating exhibited better resistance to scale
                      spallation despite faster oxidation kinetics, apparently
                      favored by phase stability over a wide temperature range.
                      Furthermore, it is shown that for a specific material, the
                      oxidation behavior can be considerably influenced by the
                      geometrical and processing parameters mentioned above. In
                      general this influence was achieved due to a variation of
                      the yttrium reservoir, mobility and/or distribution, which
                      in turn determined to which extent this element can act at
                      the surface during oxidation. Only by varying the oxygen
                      partial pressure of the atmosphere could be obtained scales
                      with different oxidation kinetics but identical in
                      morphology and composition. After assessment of these scales
                      it seemed to be that a critical TGO thickness to failure in
                      EB-PVD TBC systems exists.},
      cin          = {IEF-2},
      cid          = {I:(DE-Juel1)VDB810},
      pnm          = {Rationelle Energieumwandlung},
      pid          = {G:(DE-Juel1)FUEK402},
      typ          = {PUB:(DE-HGF)11 / PUB:(DE-HGF)3},
      url          = {https://juser.fz-juelich.de/record/2198},
}