2种C/C材料高温熔渗制备C/C-SiC-ZrC复合材料的力学性能

Mechanical properties of C/C-SiC-ZrC composites prepared by reactive melt infiltration using two kinds of C/C materials

分别以针刺编织预制体(2.5D)和三维编织预制体(3D)为增强体,采用化学气相沉积结合高温熔渗工艺制备2种不同预制体结构的C/C-SiC-ZrC复合材料。利用X射线衍射仪,扫描电镜和能谱分析仪等测试手段,对材料的微观结构进行分析,采用三点弯曲实验和压缩实验研究材料的力学性能,得出不同预制体对最终复合材料断裂性能的影响规律。结果表明:材料中的SiC与ZrC呈偏聚态分布,2.5D复合材料的弯曲强度和压缩强度高达147.38 MPa,252.4 MPa;与3D复合材料相比,2.5D复合材料强度分别提高了192%和90.7%。这主要是由于2.5D复合材料纤维含量少,孔隙多,反应后密度较高所致。

C/C-SiC-ZrC composites were fabricated by reactive melt infiltration using needling preform （2.5D） and 3-D braided preform （3D）. The structure and morphology of the composites were characterized by XRD, SEM and EDS analysis. The mechanical properties of the materials were investigated by three point bending tests. The effect of different preform on fracture behavior of the composites was studied. The results show that the SiC and ZrC phases exhibit a segregated distribution in the composites. Compared with 3D composites, the flexural strength and compressive strength of 2.5D composites are 147.38 MPa and 252.4 MPa, increased by 192%and 90.7%. This is mainly caused by the lower fibre content, the higher density after reaction and the more porous of the 2.5D composites.