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@PHDTHESIS{Rmann:1053957,
      author       = {Rüßmann, Martin},
      title        = {{E}ntwicklung von {B}eschichtungsverfahren für die
                      {H}erstellung von {W}ärmedämmschichten auf additiv
                      gefertigten {K}omponenten},
      volume       = {687},
      school       = {Bochum},
      type         = {Dissertation},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
      reportid     = {FZJ-2026-01634},
      isbn         = {978-3-95806-877-3},
      series       = {Schriften des Forschungszentrums Jülich Reihe Energie $\&$
                      Umwelt / Energy $\&$ Environment},
      pages        = {ix, 188},
      year         = {2026},
      note         = {Dissertation, Bochum, 2025},
      abstract     = {The protection of metallic combustion chamber walls and
                      high-temperature blades in aircraft turbines by ceramic
                      thermal barrier coatings (TBC) and air film cooling is
                      crucial for increasing the efficiency and service life of
                      the turbine. A further improvement in efficiency requires an
                      increase in the gas inlet temperature, which necessitates
                      the development of optimized WDS systems and cooling
                      concepts. Additive manufacturing technologies facilitate the
                      production of flow-optimized cooling holes, which form an
                      insulating layer of air on the hot WDS surface using
                      compressor air during turbine operation, thus protecting it
                      from the hot combustion gases. However, to ensure a
                      continuous air film, the cooling holes must not be blocked
                      by the bonding agent layer (bond coat) or the top coat. The
                      subsequent opening of complex geometries using mechanical
                      processes or laser technology is time-consuming and
                      cost-intensive, necessitating the development of suitable
                      coating processes that avoid blocking the cooling holes. As
                      part of this study, the propensity for blockage of several
                      bond coat production techniques was assessed, including
                      thermal spraying of a CoNiCrAlY alloy material using the
                      High Velocity Oxygen Fuel (HVOF) process and vacuum plasma
                      spraying (VPS). It was determined that the blocking issue in
                      the HVOF process can be mitigated by modifying the spray
                      angle between the torch and the substrate. Additionally,
                      oxidation-resistant nickel-aluminide diffusion layers were
                      produced on nickelbased alloys using the pack-cementation
                      process, which effectively prevented blocking. Subsequent
                      steps involved the coating of the samples using suspension
                      plasma spraying (SPS) and plasma spray physical vapor
                      deposition (PS-PVD). It was determined that the SPS process
                      necessitates suitable pretreatment of the surface, such as
                      sandblasting, to ensure stable bonding of the ceramic top
                      layer. The results also demonstrated that the PS-PVD process
                      is particularly effective in maintaining the cooling holes
                      free, as it results in effective deposition from the gas
                      phase, with most of the plasma gas flowing around the
                      cooling holes. Moreover, both experimental and
                      simulation-based evidence demonstrated that the SPS process
                      can achieve reduced blockage compared to the APS process. In
                      addition, it has been proven both experimentally and through
                      simulations that the SPS process enables reduced blockage
                      compared to atmospheric plasma spraying (APS). This is
                      achieved by adjusting the spray parameters, such as the
                      spray distance or the total gas flow rate, as well as the
                      cooling air pressure. Thermal cycling tests have also shown
                      that SPS and PS-PVD processes can be used to produce
                      coatings with a comparable or even improved service life
                      compared to APS coatings on substrates with cooling holes.
                      This research project was financially supported within the
                      framework of LuFo by the Federal Republic of Germany,
                      Federal Ministry of Economics and Climate Protection, based
                      on a resolution of the German Bundestag (FKZ: 20T1702) and
                      by Rolls-Royce Deutschland Ltd $\&$ Co KG.},
      cin          = {IMD-2},
      cid          = {I:(DE-Juel1)IMD-2-20101013},
      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-2026-01634},
      url          = {https://juser.fz-juelich.de/record/1053957},
}