TY  - GEN
A1  - Müller, Bernd Randolf
A1  - Kupsch, Andreas
A1  - Laquai, Rene
A1  - Nellesen, Jens
A1  - Tillmann, Wolfgang
A1  - Kasperovich, Galina
A1  - Bruno, Giovanni
T1  - Microstructure Characterisation of Advanced Materials via 2D and 3D X-Ray Refraction Techniques
T2  - Materials Science Forum
N2  - 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.
KW  - X-ray refraction
KW  - radiography
KW  - tomography
KW  - synchrotron X-ray refraction radiography
KW  - CT
KW  - microscopy
KW  - creep
KW  - porosity
KW  - damage evolution
KW  - additive manufacturing
KW  - metal matrix composite
Y1  - 2018
SN  - 978-3-0357-1208-7
U6  - https://doi.org/10.4028/www.scientific.net/MSF.941.2401
SN  - 0255-5476
VL  - 941
SP  - 2401
EP  - 2406
PB  - Trans Tech Publications Ltd
CY  - Zurich
ER  - 
TY  - JOUR
A1  - Mack, Daniel Emil
A1  - Laquai, Rene
A1  - Mueller, Bernd
A1  - Helle, Oliver
A1  - Sebold, Doris
A1  - Vassen, Robert
A1  - Bruno, Giovanni
T1  - Evolution of porosity, crack density, and CMAS penetration in thermal barrier coatings subjected to burner rig testing
JF  - Journal of the American Ceramic Society
N2  - 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.
KW  - characterization
KW  - CMAS
KW  - synchrotron X-ray refraction radiography
KW  - thermal barrier coatings
Y1  - 2019
U6  - https://doi.org/10.1111/jace.16465
SN  - 0002-7820
SN  - 1551-2916
VL  - 102
IS  - 10
SP  - 6163
EP  - 6175
PB  - Wiley
CY  - Hoboken
ER  -