温度脉冲方法制备碳/碳化硅复合材料界面的微观结构与性能研究

采用温度脉冲化学气相渗透沉积的方法制备了碳/碳化硅复合材料界面. 以六甲基二硅胺烷(Hexamethyldisilazane , HMDS) 为前驱体, 以3k, 三维四向的石墨化碳纤维编织体为预制体, 通过强制流动热力学梯度化学气相渗透沉积的方法(FCVI)制备出密度为1.98g·cm^-3的C _f/SiC复合材料. 运用透射电子显微镜(TEM)对复合材料的界面微观结构进行了分析. 复合材料的平均弯曲强度为458MPa, 平均断裂韧性为19.8MPa·m^1/2. 应用扫描电子显微镜(SEM)对复合材料的断裂形貌进行了分析研究.

Carbon/Silicon Carbide Composites with Interphases Processed by Temperature-pulsing Chemical Vapor Infiltration Technique

A novel method of temperature-pulsing chemical vapor infiltration (T-pulsing CVI)was introduced. And interfacial coatings of silicon carbide (SiC) layer and pyrolytic carbon (PyC) layer were processed via the route. 3D carbon fiber preforms were densified by forced-flow thermal-gradient chemical vapor infiltration (FCVI) with the precursor of hexamethyldisilazane (HMDS). The microstructure of interphases was investigated by transmission electron microscope (TEM). The configuration of specimens' fracture surface was observed by scanning electron microscope (SEM). Results show that the density of the composites is 1.98g·cm^-3. The thickness of the SiC layer estimated is 20nm, and 50nm for the PyC layer. The average flexural strength of the composites is 458MPa at room temperature, and the average fracture toughness is 19.8MPa·m^1/2.