炭纤维增强层状热解炭/碳化硅基复合材料的制备及性能研究

Preparation and microstructure properties of carbon fiber reinforced layered PyC-SiC composites

以普通炭毡为预制体,在炭纤维表面经多次反复沉积热解炭(PyC)和碳化硅(SiC)层,最终制备出炭纤维增强层状PyCSiC炭/陶复合材料。对复合材料微观结构、物相组成及断裂行为进行分析,结果表明:靠近炭纤维周围的层状PyC-SiC复合材料厚度均匀、致密,层状结构清晰,远离炭纤维处层状结构难以分辨;结合三点弯曲载荷-位移曲线及SEM断口形貌可以判断复合材料断裂方式为阶梯型断裂,裂纹在层间界面发生了明显的偏转,炭纤维增强层状PyC-SiC复合材料的韧性得到明显提高。

A pyrolytic carbon layer and a silicon carbide layer are successively deposited on the surface of a common carbon felt preform.By repeated deposition,the carbon fiber reinforced layered PyC-SiC carbon-ceramic composite is finally prepared.The microstructure,phase composition,and fracture behavior of the composite are characterized.The results show that the PyC-SiC layer near the carbon fibers is uniform and dense,and the layered structure is clear.The layered structure far from the carbon fiber is fuzzy.Combined with the three-point bending load-displacement curve and SEM fracture morphology,it can be judged that the fracture mode of the composite material is a step-type fracture,the crack deflected obviously at the interface between layers,and the toughness of carbon fiber reinforced layered PyC-SiC composites has been significantly improved.