Coupled damage evolution of C_f/SiC composites across a full oxygen concentration gradient at elevated temperature via synchrotron in-situ CT and deep learning

TY - JOUR

T1 - Coupled damage evolution of Cf/SiC composites across a full oxygen concentration gradient at elevated temperature via synchrotron in-situ CT and deep learning

AU - Li, Shaoling

AU - Zhang, Zhongfang

AU - Xue, Kaiyuan

AU - He, Rujie

AU - Huang, Yixing

AU - Xi, Li

AU - Li, Ying

N1 - Publisher Copyright: © 2026

PY - 2026/12/10

Y1 - 2026/12/10

N2 - To elucidate the effect of environmental oxygen concentration on damage evolution in Cf/SiC composites at high temperature, an integrated platform incorporating ultrahigh‑temperature in‑situ loading with synchrotron‑radiation μCT (SR‑μCT) was constructed. This platform enabled real‑time observation of coupled thermo‑mechanical‑oxidative damage in Cf/SiC at 1400 °C under 0, 0.5 vol.%, 5 vol.%, and 21 vol.% O2. Combined with the nnU‑Net deep‑learning framework, the 3D evolution of coating cracks, voids, oxidation damage, and delamination was visualised and quantified. Integrating SR‑μCT with fractography elucidated the sequential evolution from damage initiation to final failure. Tensile strength decreased with increasing oxygen concentration. Under inert conditions, coating cracks propagated periodically with continuous nucleation, void morphology remained stable, and failure was abrupt and brittle. At O2 ≥ 0.5 vol.%, oxidation‑induced damage initially propagated along pre‑existing coating cracks; fibres in the crack‑contact zone were oxidised first, and damage extended along the fibre orientation, resulting in a 3D damage field aligned with the crack path. At O2 ≥ 5 vol.%, oxidation induced new microvoids whose growth and coalescence increased void volume and formed a 3D network. Collectively, these processes established a cycle where voids accelerated oxygen diffusion, accelerated diffusion induced further damage, and damage produced more voids. This work provides an effective four-dimensional analysis method for investigating the coupled evolution of multiple damage modes in ceramic-matrix composites under high-temperature oxidation.

AB - To elucidate the effect of environmental oxygen concentration on damage evolution in Cf/SiC composites at high temperature, an integrated platform incorporating ultrahigh‑temperature in‑situ loading with synchrotron‑radiation μCT (SR‑μCT) was constructed. This platform enabled real‑time observation of coupled thermo‑mechanical‑oxidative damage in Cf/SiC at 1400 °C under 0, 0.5 vol.%, 5 vol.%, and 21 vol.% O2. Combined with the nnU‑Net deep‑learning framework, the 3D evolution of coating cracks, voids, oxidation damage, and delamination was visualised and quantified. Integrating SR‑μCT with fractography elucidated the sequential evolution from damage initiation to final failure. Tensile strength decreased with increasing oxygen concentration. Under inert conditions, coating cracks propagated periodically with continuous nucleation, void morphology remained stable, and failure was abrupt and brittle. At O2 ≥ 0.5 vol.%, oxidation‑induced damage initially propagated along pre‑existing coating cracks; fibres in the crack‑contact zone were oxidised first, and damage extended along the fibre orientation, resulting in a 3D damage field aligned with the crack path. At O2 ≥ 5 vol.%, oxidation induced new microvoids whose growth and coalescence increased void volume and formed a 3D network. Collectively, these processes established a cycle where voids accelerated oxygen diffusion, accelerated diffusion induced further damage, and damage produced more voids. This work provides an effective four-dimensional analysis method for investigating the coupled evolution of multiple damage modes in ceramic-matrix composites under high-temperature oxidation.

KW - C/SiC composite materials

KW - Deep learning

KW - Oxidation damage

KW - Oxygen concentration

KW - Synchrotron X-ray micro-CT

UR - https://www.scopus.com/pages/publications/105035104002

U2 - 10.1016/j.jmst.2026.03.049

DO - 10.1016/j.jmst.2026.03.049

M3 - Article

AN - SCOPUS:105035104002

SN - 1005-0302

VL - 274

SP - 169

EP - 181

JO - Journal of Materials Science and Technology

JF - Journal of Materials Science and Technology

ER -