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Analysis of the effective thermoelastic properties and stress fields in silicon nitride based on EBSD data

 
: Othmani, Y.; Böhlke, T.; Lube, T.; Fellmeth, A.; Chlup, Z.; Colonna, F.; Hashibon, A.

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Postprint urn:nbn:de:0011-n-3821286 (3.0 MByte PDF)
MD5 Fingerprint: 1a57443228a9e826081d81e512c0446a
Erstellt am: 27.11.2018


Journal of the European Ceramic Society 36 (2016), Nr.5, S.1109-1125
ISSN: 0955-2219
European Commission EC
FP7-NMP; 263476; RoLiCer
Englisch
Zeitschriftenaufsatz, Elektronische Publikation
Fraunhofer IWM ()
silicon nitride; EBSD data; Hashin Shtrikman bounds; finite element analysis; thermomechanical behavior

Abstract
The present work focuses on the determination of the effective thermoelastic properties and the statistical characterization of stress fluctuations in silicon nitride's local phases. For that purpose, full field finite element solutions have been considered, based on 3D electron backscatter diffraction (EBSD) data of silicon nitride. A second-order mean field homogenization scheme, consisting in Hashin-Shtrikman bounds, has been also considered. Ab-initio simulations have been performed in order to determine the temperature-dependent elastic properties of the local phases. The isotropic material microstructure has been checked based on both experimental results and full field solutions. The effective thermoelastic properties have been assessed with the newly obtained experimental results. The stress fluctuations within silicon nitride's local phases have been examined under mechanical and thermal loadings. It has been shown that the amorphous phase is the most vulnerable to fracture and to micro-cracks initiation.

: http://publica.fraunhofer.de/dokumente/N-382128.html