管状C/SiC复合材料高温空气氧化行为与宏细观建模研究OA北大核心CSTPCD

Oxidation damage is one of the main factors affecting the life of C/SiC composite nozzle used in rocket engines.To accurately predict the oxidation damage of C/SiC composite nozzle,we explored the oxidation behavior of the tubular C/SiC composites which had a similar shape to nozzle.Evolution of their composition,structure,and mechanical properties was investigated at different temperatures ranging from 900 to 1300℃.The results showed that the tubular C/SiC composites exhibited diffusion-controlled oxidation characteristics under the high-temperature environment.Their mass and residual strength decreased as a power function with time,and decline rate was positively correlated with temperature.Moreover,based on the theory of oxidation kinetics and mass transfer,a macro-meso oxidation model was established to simulate the oxidation process of tubular C/SiC composites in high-temperature environment to timely predict the evolution of their mass and residual strength.Consequentely,all the predicted results of the model fitted well with the experimental data.Our investigation consolidate that this macro-meso oxidation model is powerfull to predict the oxidation behavior and the life-span of C/SiC composite nozzle.