An analytical model for the high temperature fracture strength of SiC fiber reinforced ceramic matrix composites considering oxidation and residual thermal stresses

As a promising high temperature structural material, ceramic matrix composites have attracted much attention due to their excellent thermo-mechanical properties. The present work develops a physics-based temperature dependent analytical model of fracture strength at high temperature oxidation environment for SiC fiber reinforced ceramic matrix composites (SiCf/CMCS). The combined effects of temperature, strength of constituent material, high temperature oxidation and residual thermal stress on the fracture strength are included in the proposed model. It is verified by the reported experimental results and comparison with other models, and it shows better agreement. Moreover, the influencing factors analysis regarding the evolution of fracture strength with oxidation temperature and time, fiber content and Young's modulus, and residual thermal stress are performed. This study contributes a reliable theoretical model for predicting high temperature fracture strength of SiCf/CMCS, and which is helpful for the mechanical property evaluation and property optimization under extreme environment.

Automated summary

In this study, a physics-based temperature dependent analytical model for predicting the fracture strength of SiC fiber reinforced ceramic matrix composites (SiCf/CMCS) under high temperature oxidation environment is developed. The effects of temperature, strength of constituent material, high temperature oxidation, and residual thermal stress on fracture strength are included in the model. The model is verified by experimental results and comparison with other models, showing better agreement. Furthermore, the study analyzes the influencing factors of fracture strength evolution with oxidation temperature and time, fiber content and Young's modulus, and residual thermal stress. The reliable theoretical model provided in this study contributes to the prediction of high temperature fracture strength of SiCf/CMCS, and is helpful for mechanical property evaluation and property optimization under extreme environments.