论文部分内容阅读
以准三维针刺炭纤维毡为预制体,采用化学气相渗透工艺在预制体中炭纤维/基体炭之间制备C-SiC-TaC-C复合界面,利用树脂浸渍-炭化工艺对材料进一步增密,获得含C-SiC-TaC-C界面的C/C复合材料。研究了1400～2500℃不同温度热处理前后复合材料的微观结构和力学性能。结果表明:热处理前,SiC-TaC界面为管状结构,复合材料的抗弯强度为241.6MPa,以脆性断裂为主;经1400～1800℃热处理后,TaC界面破坏呈颗粒状,复合材料的平均抗弯强度下降到238.9～226.1MPa,其断裂方式不变,但断裂位移由0.7mm增至1.0mm;经2000～2500℃热处理后,SiC、TaC界面均受到破坏,复合材料平均抗弯强度急剧下降至158.7～131.8MPa,断裂方式由脆性断裂转变为假塑性断裂。
The C-SiC-TaC-C composite interface was prepared by chemical vapor infiltration in the quasi-three-dimensional acupuncture carbon fiber mat, and the material was further densified by the resin impregnation-carbonization process , C / C composites with C-SiC-TaC-C interface were obtained. The microstructure and mechanical properties of the composites before and after heat treatment at 1400 ~ 2500 ℃ were studied. The results show that the interface of SiC-TaC has a tubular structure before heat treatment. The flexural strength of the composites is 241.6 MPa, which is mainly brittle fracture. After heat treatment at 1400-1800 ℃, the interfacial failure of the composites is granular, The flexural strength decreased to 238.9 ~ 226.1MPa, the fracture mode remained unchanged, but the fracture displacement increased from 0.7mm to 1.0mm. After heat treatment at 2000 ~ 2500 ℃, the interface between SiC and TaC was destroyed, and the average flexural strength of the composites decreased sharply To 158.7 ~ 131.8MPa, the fracture mode changed from brittle fracture to pseudoplastic fracture.