【摘要】 为了探究C纤维和SiC纤维对SiC陶瓷基复合材料力学性能的影响,采用化学气相浸渗法(CVI)制备了纤维束复合材料Mini-C/SiC和Mini-SiC/SiC,测试了C纤维束、SiC纤维束、Mini-C/SiC和Mini-SiC/SiC复合材料的拉伸强度,利用两参数Weibull分布模型研究了强度分布,并观察了复合材料的断口形貌。结果表明:两参数Weibull分布可有效合理地表征强度分布,并准确地进行强度预测。Mini-C/SiC复合材料的拉伸强度高于Mini-SiC/SiC复合材料,且C纤维束和Mini-C/SiC复合材料拉伸强度的分散性低于SiC纤维束和Mini-SiC/SiC复合材料。C纤维束发生韧性断裂,SiC纤维束发生脆性断裂。当基体裂纹达到饱和状态时,Mini-C/SiC复合材料继续变形直至断裂,而Mini-SiC/SiC复合材料随即发生断裂,Mini-C/SiC复合材料的断口主要以纤维丝和纤维簇的拔出为主,而Mini-SiC/SiC复合材料的断口主要以纤维丝的拔出为主。该实验结果将为SiC陶瓷基复合材料的设计与制备提供参考与借鉴。更多还原

【Abstract】 In order to investigate the impact of C fiber and SiC fiber on the mechanical properties of SiC ceramic matrix composites, Mini-C/SiC and Min-SiC/SiC fiber bundle composites were prepared through chemical vapor infiltration(CVI). Tensile strength of C and SiC fiber bundles, Mini-C/SiC and Mini-SiC/SiC composites was tested. Strength distribution was studied through two-parameter Weibull distribution model. Fracture morphology of the composites was observed. The results show that the two-parameter Weibull distribution model can effectively and reasonably characterize the strength distribution and accurately predict the strength. The tensile strength of Mini-C/SiC composite is higher than that of Mini SiC/SiC composite, and the tensile strength dispersion of C fiber bundle and Mini-C/SiC composite is lower than that of SiC fiber bundle and Mini-SiC/SiC composite. Tough fracture occurs in C fiber bundle and brittle fracture occurs in SiC fiber bundle. When the matrix cracks reach saturation state, the Mini-C/SiC composite continues to deform until it breaks. However, the Mini-SiC/SiC composite is fractured immediately. The main fracture morphology of Mini-C/SiC composite is the pull-out of filaments and fiber clusters, while the main fracture morphology of Mini-SiC/SiC composite is the pull-out of filaments. The experimental results will provide references for the design and preparation of SiC ceramic matrix composites.更多还原