Z向穿刺结构参数对Cf/Al复合材料显微组织与剪切性能的影响

采用真空压力浸渗法制备了4种叠层穿刺结构Cf/Al复合材料,研究了Z向穿刺结构参数对Cf/Al复合材料致密度、显微组织与剪切性能的影响。结果表明,Z向穿刺结构参数对Cf/Al复合材料的致密度、显微组织以及剪切性能影响较大,Z向穿刺纤维束为单股,针距分别为3mm和4mm时的Cf/Al复合材料致密度、剪切强度、模量分别为95.0%、69.9MPa、7.47GPa和95.5%、65.3MPa、8.38GPa;Z向穿刺纤维束为双股,针距分别为3mm和4mm时的Cf/Al复合材料致密度、剪切强度、模量分别为96.3%、78.6MPa、8.26GPa和96.0%、63.7MPa、8.12GPa。其中,Z向穿刺纤维束为双股,针距为3mm时的Cf/Al复合材料的显微组织较其余3种复合材料的显微组织而言,其纤维丝分布均匀,未发现明显的微孔缺陷。复合材料剪切破坏首先出现在V型口基体与界面损伤处,裂纹与剪切力方向呈45°扩展,经纱纤维束的屈曲变形、纬纱纤维束的挤压变形以及Z向穿刺纤维束的偏折导致复合材料最终失效。

Effects of Z-direction Puncture Structural Parameters on Microstructures and Shear Properties of Cf/Al Composites

Four kinds of laminated puncture structural Cf/Al composites with volume fraction of 47.5%of carbon fiber were fabricated by vacuum pressure infiltration.The effects of Z-direction puncture structural parameters on the density,microstructure and shearing properties of Cf/Al composites were investigated.The results reveal that the Z-direction puncture structural parameters have great influence on the density,microstructure and shearing properties of Cf/Al composites.With Z-direction puncture fiber bundles of single stock,and the needle spacing of 3 mm/needle and 4 mm/needle,respectively,the density,shearing strength and modulus of Cf/Al composites are 95.0%,69.9 MPa,7.47 GPa and 95.5%,65.3 MPa,8.38 GPa,respectively.With Z-direction puncture fiber bundles of double stock and the needle spacing of 3 mm/needle and 4 mm/needle,respectively,the density,shearing strength and modulus of Cf/Al composites reach up to 96.3%,78.6 MPa,8.26 GPa and 96.0%,63.7 MPa,8.12 GPa,respectively.Compared with the microstructures of the other three composites,with Z-direction puncture fiber bundles of double socks,and the needle spacing of 3 mm/needle of Cf/Al composites,the fiber filaments are evenly distributed and absence of obvious micro-voids defects.Shear failure of composites is attributed to occurrence of the crack at the matrix and interface damage of V-notch,and the cracks and shear force extending at 45°as well as the buckling deformation of the warp fiber bundles,the extrusion deformation of the weft fiber bundles and the deflection of the Z-direction puncture fiber bundles lead to the ultimate failure of composites.