@article{MackLaquaiMuelleretal.2019,
  author    = {Mack, Daniel Emil and Laquai, Rene and Mueller, Bernd and Helle, Oliver and Sebold, Doris and Vassen, Robert and Bruno, Giovanni},
  title     = {Evolution of porosity, crack density, and CMAS penetration in thermal barrier coatings subjected to burner rig testing},
  series = {Journal of the American Ceramic Society},
  volume    = {102},
  journal   = {Journal of the American Ceramic Society},
  number    = {10},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0002-7820},
  doi       = {10.1111/jace.16465},
  pages     = {6163 -- 6175},
  year      = {2019},
  abstract  = {Degradation of thermal barrier coatings (TBCs) in gas-turbine engines due to calcium-magnesium-aluminosilicate (CMAS) glassy deposits from various sources has been a persistent issue since many years. In this study, state of the art electron microscopy was correlated with X-ray refraction techniques to elucidate the intrusion of CMAS into the porous structure of atmospheric plasma sprayed (APS) TBCs and the formation and growth of cracks under thermal cycling in a burner rig. Results indicate that the sparse nature of the infiltration as well as kinetics in the burner rig are majorly influenced by the wetting behavior of the CMAS. Despite the obvious attack of CMAS on grain boundaries, the interaction of yttria-stabilized zirconia (YSZ) with intruded CMAS has no immediate impact on structure and density of internal surfaces. At a later stage the formation of horizontal cracks is observed in a wider zone of the TBC layer.},
  language  = {en}
}
@misc{MuellerKupschLaquaietal.2018,
  author    = {M{\"u}ller, Bernd Randolf and Kupsch, Andreas and Laquai, Rene and Nellesen, Jens and Tillmann, Wolfgang and Kasperovich, Galina and Bruno, Giovanni},
  title     = {Microstructure Characterisation of Advanced Materials via 2D and 3D X-Ray Refraction Techniques},
  series = {Materials Science Forum},
  volume    = {941},
  journal   = {Materials Science Forum},
  publisher = {Trans Tech Publications Ltd},
  address   = {Zurich},
  isbn      = {978-3-0357-1208-7},
  issn      = {0255-5476},
  doi       = {10.4028/www.scientific.net/MSF.941.2401},
  pages     = {2401 -- 2406},
  year      = {2018},
  abstract  = {3D imaging techniques have an enormous potential to understand the microstructure, its evolution, and its link to mechanical, thermal, and transport properties. In this conference paper we report the use of a powerful, yet not so wide-spread, set of X-ray techniques based on refraction effects. X-ray refraction allows determining internal specific surface (surface per unit volume) in a non-destructive fashion, position and orientation sensitive, and with a nanometric detectability. We demonstrate showcases of ceramics and composite materials, where microstructural parameters could be achieved in a way unrivalled even by high-resolution techniques such as electron microscopy or computed tomography. We present in situ analysis of the damage evolution in an Al/Al2O3 metal matrix composite during tensile load and the identification of void formation (different kinds of defects, particularly unsintered powder hidden in pores, and small inhomogeneity's like cracks) in Ti64 parts produced by selective laser melting using synchrotron X-ray refraction radiography and tomography.},
  language  = {en}
}