热处理工艺对Mini C/SiC复合材料拉伸性能和强度分布的影响

Influence of Heat Treatment Processes on Tensile Properties and Strength Distribution of Mini C/SiC Composites

采用5种工艺制备了C纤维束增韧SiC陶瓷基复合材料(Mini C/SiC),研究了热处理工艺对不同制备工艺条件下Mini C/SiC复合材料拉伸性能和强度分布的影响。实验结果表明:在不进行热处理的Mini C/SiC复合材料中引入热解炭(PyC)界面相可提高拉伸性能和强度稳定性。与不进行热处理的MiniC/SiC复合材料相比,对引入PyC界面相复合材料的C纤维束和/或PyC界面相进行热处理均可提高拉伸性能。热处理温度小于等于1700℃时,先对C纤维进行热处理然后再沉积PyC界面相的MiniC/SiC复合材料,其拉伸性能最好。热处理温度为2000℃时,先对C纤维沉积PyC界面相然后再进行热处理的Mini C/SiC复合材料,其拉伸性能最好。热处理温度对Mini C/SiC复合材料变形行为有着显著的影响,热处理温度不同时,复合材料表现出了不同的变形行为。

C fiber bundle toughened SiC ceramic matrix composites(Mini C/SiC)were fabricated by five different processes.The influence of heat treatment processes on the tensile properties and strength distribution of Mini C/SiC composites under different preparation conditions was studied.The experimental results showed that the introduction of PyC interphase into Mini C/SiC composite without heat treatment improved the tensile properties and strength stability.Compared with Mini C/SiC composite without heat treatment,the tensile properties of the composites with PyC interphase were improved by heat treatment for C fiber bundle and/or PyC interphase.When the heat treatment temperature was less than or equal to 1700℃,Mini C/SiC composites with C fibers deposited PyC interphase after heat treatment had the best mechanical properties.When the temperature of heat treatment was 2000℃,the tensile properties of Mini C/SiC composites were the best,which were prepared by deposition of PyC interphase on C fibers and then heat treatment.The heat treatment temperature had significant effect on the deformation behavior of Mini C/SiC composites.The composites showed different deformation behavior when the heat treatment temperature was different.