细编穿刺C/C-SiC复合材料螺栓连接件的制备和力学性能研究

Preparation and mechanical properties of finely braided and punctured C/C-SiC composite bolted

本文以细编穿刺毡为预制体,通过聚合物浸渍一裂解法(PIP)和化学气相沉积法(CVD)相结合的工艺,制备了密度为1.95g/cm^(3)的C/C-SiC复合材料,并沿不同方向加工出标准测试件和规格为M10、M8、M6的螺栓连接件。利用扫描电子显微镜(SEM)和X射线衍射仪(XRD)对材料的微观形貌及结构进行表征,并对测试件和螺栓的力学性能进行分析。结果表明,沿平行于纤维方向(平行方向)加工的测试件具有更优的力学性能。螺栓连接件的抗拉强度与其规格及螺母数量有关,沿平行于纤维方向加工的M8螺栓和双螺母的配合具有最佳的抗拉强度,为140.2MPa,而剪切强度三种螺栓基本相同,约为60MPa。

In this paper,a fine-woven punched felt was used as a preform to prepare a C/C-SiC composite with a density of 1.95 g/cm^(3).The preparation process involved a combination of polymer impregnation-pyrolysis(PIP)and chemical vapor deposition(CVD).Standard test parts and bolt connectors of M10,M8,and M6 specifications were processed in different directions.Scanning electron microscopy(SEM)and X-ray diffractometry(XRD)were employed to characterize the microscopic morphology and structure of the material.Furthermore,the mechanical properties of the test pieces and bolts were analyzed.The results indicate that test pieces processed parallel to the fiber direction exhibit superior mechanical properties.The tensile strength of bolted connectors is dependent on their specifications and the number of nuts.Notably.the combination of an M8 bolt and double nut machined parallel to the fiber direction demonstrates the highest tensile strength at 140.2 MPa.Additionally,the shear strength of the three types of bolts is approximately 60 MPa.