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@PHDTHESIS{Rezanka:279599,
      author       = {Rezanka, Stefan},
      title        = {{A}bscheidung von {W}ärmedämmschichtsystemen mit dem
                      {P}lasma {S}pray-{P}hysical {V}apor {D}eposition-
                      ({PS}-{PVD}-) {P}rozess - {U}ntersuchung des {P}rozesses und
                      der hergestellten {S}chichten},
      volume       = {290},
      school       = {Ruhr Universität Bochum},
      type         = {Dr.},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
      reportid     = {FZJ-2015-07483},
      isbn         = {978-3-95806-095-1},
      series       = {Schriften des Forschungszentrums Jülich, Reihe Energie
                      $\&$ Umwelt / Energy $\&$ Environment},
      pages        = {XII, 204 S.},
      year         = {2015},
      note         = {Ruhr Universität Bochum, Diss., 2015},
      abstract     = {The growing awareness in society about the limitation in
                      resources, especially fossil fuels, has led to an important
                      research and development aim on new and existing
                      technologies to increase the efficiency of energy
                      converters. The application of thermal barrier coatings
                      (TBC) enables to increase the inlet temperature of gas
                      turbines and thus the degree of effectiveness [1, 2]. At
                      present, TBCs are deposited either by atmospheric plasma
                      spraying (APS) or by electron beam-physical vapor deposition
                      (EB-PVD) [1, 2]. The relatively new Plasma Spray-Physical
                      Vapor Deposition (PS-PVD) based on low pressure plasma
                      spraying (LPPS) combines the advantages of APS and EB-PVD,
                      in particular high deposition rates, relatively low
                      manufacturing costs (APS) and deposition of columnar
                      microstructures (EBPVD). Hence, PS-PVD coatings show high
                      strain tolerance making them suitable for the hottest
                      sections of the turbine [3-5]. In this work, the properties
                      of the coatings were investigated and related to the
                      application. The coating process was optimized by
                      introducing a pre-oxidation of the bondcoat surface carried
                      out prior to PS-PVD deposition, which leads to an
                      improvement of the durability of PS-PVD-TBCs above the level
                      of the conventional APS TBCs. The positive effect of the
                      preoxidation had already been indicated in [3] and was
                      investigated here. Also, the feasibility to coat real
                      geometries was proven in this work by application on turbine
                      vane models. An increased susceptibility to high temperature
                      corrosion by mineral deposits of the composition calcium
                      magnesium alumino silicate (CMAS) had been assumed before,
                      due to the high amount of open porosity in the columnar
                      structure. In this work, by means of modified burner rig
                      tests, it was shown that the resistance against this kind of
                      attack is equivalent to the one encountered in EB-PVD
                      coatings and only slightly below the one present in APS
                      coatings. Besides chemical damage, ingested CMAS particles
                      can limit the durability of coatings also by erosion.
                      Implementing standardized erosion tests, an increased
                      erosion resistance of deposited coatings with a plasma
                      containing H2, could be confirmed [4-6]. Coatings obtained
                      by this parameter showed comparable properties to APS
                      coatings, although the resistance of EB-PVD coatings was not
                      reached. The second major aim of this work was to develop a
                      better understanding of the PS-PVD process in order to
                      enable further optimization and reliable industrial
                      application. This task requires models to describe the
                      phenomena experienced by the material during evaporation,
                      transport in the plasma plume and coating deposition. An
                      important result in [3] was that PSPVD was assumed to be
                      featured not only by vapor deposition, but by a combination
                      of vapor- and nano crystalline cluster deposition. In order
                      to examine the crystal structure of the coatings,
                      transmission electron microscopy was carried out to prove
                      such deposition of clusters. The observed column
                      substructures with semi-single crystal structure did not
                      show any overall preferred orientation. This result was also
                      confirmed by X-ray diffraction analysis. However, local
                      textures in single column branches were found. These results
                      are not in contradiction to the description of cluster
                      deposition, but do not confirm it directly. [...]},
      cin          = {IEK-1},
      cid          = {I:(DE-Juel1)IEK-1-20101013},
      pnm          = {113 - Methods and Concepts for Material Development
                      (POF3-113) / HITEC - Helmholtz Interdisciplinary Doctoral
                      Training in Energy and Climate Research (HITEC)
                      (HITEC-20170406)},
      pid          = {G:(DE-HGF)POF3-113 / G:(DE-Juel1)HITEC-20170406},
      typ          = {PUB:(DE-HGF)11 / PUB:(DE-HGF)3},
      url          = {https://juser.fz-juelich.de/record/279599},
}