磁场作用下氧化石墨烯包覆羟基氧化铁增强碳纤维/环氧树脂复合材料的层间断裂韧性

Enhancing interlaminar fracture toughness of carbon fiber/epoxy resin composite with graphene oxide coated hydroxy iron oxide under magnetic field

为有效提高碳纤维/环氧树脂(CF/EP)复合材料层合板的层间断裂韧性,采用静电自组装技术制备了一种由氧化石墨烯包覆针状羟基氧化铁而成的纳米复合粒子(GO@FeOOH),分散在EP基体中并借助磁场诱导以提高增韧效果。通过双悬臂梁实验(DCB)测试GO@FeOOH/CF/EP层合板的Ⅰ型层间断裂韧性(G_(ⅠC)),重点考察复合粒子和磁场诱导对G_(ⅠC)的影响。结果表明:质量分数0.5%的GO@FeOOH即可显著增强CF/EP复合材料的层间断裂韧性,GO@FeOOH/CF/EP的初始裂纹G_(ⅠC)(0.53 kJ·m^(-2))和裂纹扩展G_(ⅠC)(0.71 kJ·m^(-2))较CF/EP分别提高了34.2%和44.9%;另一方面,磁场诱导使GO@FeOOH沿着磁场方向发生了取向,进一步显著提高了增韧效果,初始裂纹G_(ⅠC)和裂纹扩展G_(ⅠC)较CF/EP分别提高了112.6%和93.9%;该复合材料的层间增韧机理主要包括粒子的拔断与脱粘以及基体的局部塑性形变,磁场诱导后,粒子的拔断成为主导的增韧机理。

To effectively improve the interlaminar toughness of carbon fiber/epoxy resin(CF/EP) composite laminates,toughening nanoparticles(GO@FeOOH) were prepared by electrostatic self-assembly technology,which was the needle-like hydroxy iron oxide coated with graphene oxide.Dispersed in EP matrix and induced by magnetic field,the toughening effect of GO@FeOOH nanoparticles was significantly improved.The mode Ⅰ interlaminar toughness(G_(ⅠC)) of GO@FeOOH/CF/EP laminates was examined by double cantilever beam test.The effects of GO@FeOOH and magnetic field induction on G_(ⅠC) were investigated.The results show that the GO@FeOOH can significantly enhance the interlaminar properties of CF/EP composite even at a low content of 0.5%(mass fraction),and the initial crack G_(ⅠC)(0.53 kJ·m^(-2)) and crack propagation G_(ⅠC)(0.71 kJ·m^(-2)) of GO@FeOOH/CF/EP are 34.2% and 44.9% higher than those of CF/EP,respectively.On the other hand,the magnetic field induced GO@FeOOH orientation along the magnetic field direction,further significantly improved the toughening effect,the initial crack G_(ⅠC) and crack propagation G_(ⅠC) increased 112.6% and 93.9% compared with CF/EP,respectively.The interlaminar toughening mechanism of the composite mainly includes the pull-out and debonding of the nanoparticles and the local plastic deformation of the matrix,and the pull-out of particles becomes the dominant toughening mechanism after the induction of magnetic field.