In-situ X-ray microtomography characterization of damage in SiC/SiC minicomposites

Camille Chateau (1) , Lionel Gélébart (1) , Michel Bornert (2, 3) , Jérôme Crépin (4) , Elodie Boller (5) , C. Sauder (1) , Wolfgang Ludwig (6)

1 SRMA - Service des Recherches Métallurgiques Appliquées
2 navier umr 8205 - Laboratoire Navier
3 LMS - Laboratoire de mécanique des solides
4 CDM - Centre des Matériaux
5 ESRF - European Synchrotron Radiation Facility
6 MATEIS - Matériaux, ingénierie et science [Villeurbanne]

The purpose of the present study is to characterize matrix crack propagation and fiber breaking occurrences within SiC/SiC minicomposite in order to validate later on a multiscale damage model at the local scale. An in-situ X-ray microtomography tensile test was performed at the European Synchrotron Radiation Facility (ESRF, ID19 beamline) in order to obtain 3-dimensional (3D) images at six successive loading levels. Results reveal a slow and discontinuous propagation of matrix cracks, even after the occurrence of matrix crack saturation. A few fiber failures were also observed. However, radiographs of the whole length (14 mm) of the minicomposites under a load and after the failure were more appropriate to get statistical data about fiber breaking. Thus, observations before the ultimate failure revealed only a few fibers breaking homogenously along the minicomposite. In addition, an increase in fiber breaking density in the vicinity of the fatal matrix crack was observed after failure. These experimental results are discussed in regards to assumptions used in usual 1-dimensional (1D) models for minicomposites.

Mots clés: Ceramic-matrix composites (CMCs); Matrix cracking; Damage mechanics; X-ray computed microtomography (μ-CT)

Domaines: Matériaux

Camille Chateau, Lionel Gélébart, Michel Bornert, Jérôme Crépin, Elodie Boller, et al.. In-situ X-ray microtomography characterization of damage in SiC/SiC minicomposites. Composites Science and Technology, 2011, 71 (6), pp.916-924. ⟨10.1016/j.compscitech.2011.02.008⟩. ⟨hal-00736300⟩