Micromechanics-based simulation of B4C-TiB2 composite fracture under tensile load

• Published in: Journal of the European Ceramic Society 2022-11, Vol.42 (14), p.6364-6378
• Main Authors: Dai, Jingyao, J. Pineda, Evan, A. Bednarcyk, Brett, Singh, Jogender, Yamamoto, Namiko
• Format: Article
• Language: English
• Subjects: Boron carbide; Fracture toughness; Micro-crack toughening; Micromechanics Modeling
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2022.07.010

Micromechanics modeling was performed to study the effects of thermal residual stress, weak interphases, TiB2 volume fraction and particle size on the mechanical responses and fracture behaviors of B4C-TiB2 composites. Experimentally observed fracture behaviors including micro-cracking and crack deflection were successfully captured. The weak interphases at B4C-TiB2 boundaries and the thermal residual stress induced during cooling by the large CTE mismatch between B4C and TiB2 were identified as two major factors to promote micro-cracking that caused the enhanced progressive failure behavior. Micro-cracking was enhanced with higher TiB2 volume fraction due to higher fraction of weak interphase and material affected by thermal residual stress. Meanwhile, micro-cracking behaviors exhibited limited change with varying TiB2 particle sizes. This modeling study successfully captured the main fracture behaviors and their trends by varying micro-structures of B4C-TiB2 composites and can potentially aid microstructure design of tougher B4C-TiB2 composites in the future.