In situ X-ray tomography characterisation of 3D deformation of C/C-SiC composites loaded under tension

Yang Chen (1) , Yuan Shi (2) , Camille Chateau (3) , James Marrow (1)

1 Department of Materials, University of Oxford;
2 Institute of Structures and Design
3 NAVIER UMR 8205 - Laboratoire Navier

C/C-SiC composites fabricated through Liquid Silicon Infiltration were tested under monotonic tension with in situ X-ray computed tomography. The specimens had different fibre orientations with respect to the tensile direction, 0◦/90◦ and ±45◦, such that the tension accounted for in-axis and off-axis loads, respectively. The 3D XCT images provided explicit visualisations and quantitative measurements of the distributions of SiC-Si and the orientations of the C fibre bundles. The full-field displacement and strain fields were measured by Digital Volume Correlation, observing a difference in the local deformations in response to the in-axis and off-axis loading. In both specimens, the tensile load triggered significant strain localisations at low stress (<50 MPa). Strong local deformations, observed at both low and high applied stresses, were mostly in the through-thickness direction, indicating local delamination. These observations show the importance of residual stresses to damage development in C/C-SiC composites.

Mots clés: Ceramic-matrix composites (CMCs); Mechanical properties; Micro-mechanics; CT analysis

Domaines: Mécanique des matériaux [physics.class-ph]

Yang Chen, Yuan Shi, Camille Chateau, James Marrow. In situ X-ray tomography characterisation of 3D deformation of C/C-SiC composites loaded under tension. Composites Part A: Applied Science and Manufacturing, 2021, 145, pp.106390. ⟨10.1016/j.compositesa.2021.106390⟩. ⟨hal-03318660⟩