MoSi_2-SiC抗氧化涂层对碳/碳复合材料弯曲性能的影响

INVESTIGATION OF MICROSTRUCTURE AND FLEXURAL BEHAVIOR FOR OXIDATION PROTECTION COATED C/C COMPOSITES

在 C/C复合材料表面制备了 Mo Si2 - Si C抗氧化涂层 ,分析了涂层工艺对 C/C复合材料组织的影响 ,测试了材料的室温弯曲力学性能。结果表明 ,该工艺在 C/C复合材料表面生成抗氧化涂层的同时 ,基材内部的层间和纤维束界面 ,以及孔隙周围也被硅化。C/C复合材料经涂层工艺处理后 ,弯曲断裂行为发生改变 ,弯曲强度明显升高 ,塑性有一定程度的降低。

Mechanical properties of MoSi 2 SiC oxidation resistant coated C/C composites were investigated by three points bending tests. The microstructure of coated C/C composites and flexural fracture surface, and the interface characteristics of C/C composites were investigated; the influences of oxidation protection coating and its process on the flexural mechanical behavior of these materials were analyzed. The results showed that with the progress of the coating process, SiC conversion layer was formed in the interfaces of carbon fiber/carbon matrix and fiber bundle/matrix, and open pores or gaps existing within the composites. On the other hand, the pyro carbon matrix converted into SiC was easier than the carbon fiber. After infiltration process, the fracture behavior of C/C composite was changed. Also the correlation between microstructure and fracture behavior was discussed with the SEM results.