取向氧化石墨烯增强碳纤维/环氧复合材料的构筑及其增强机理研究

Carbon fiber/epoxy composites are widely applied in high-tech fields such as automobiles, aeronautics and astronautics due to their high specific strength, high specific stiffness, good anti-fatigue fracture properties, corrosion resistance, and good structure and size stability. However, the carbon fiber/epoxy composites are known to be relatively weak in the through-thickness direction. For example, the interlaminar cracking strength and peeling strength between the fibers and the resin are relatively poor, that is, the interlaminar shear property is relatively poor. The applicant is inspired from a principle that in a honeycomb panel model, the honeycomb core mainly bears a lateral shearing force and adopts magnetic field orientated graphene oxide (modified by Fe3O4) to reinforce the interlaminar shear property of the carbon fiber/epoxy composites. In the project, influences of parameters such as magnetic field strength, resin viscosity and compound processes on microstructures and properties of the composites are studied systematically, and a preparation method for a magnetic field orientated graphene oxide-reinforced carbon fiber composite is determined. Furthermore, a reinforcing mechanism of the orientated graphene oxide on the carbon fiber composite is explored under the effect of magnetic field orientation by analyzing the microstructures such as orientation state and dispersion situation of graphene oxide in the composite, and interfacial adhesion situation between the carbon fibers and epoxy resin.

碳纤维/环氧复合材料因具有比强度和比刚度高，抗疲劳断裂性能好，耐腐蚀，结构尺寸稳定性好等的优点，而被广泛应用于汽车、航空航天等高科技领域。但是碳纤维复合材料在厚度方向的强度相对较弱，例如，纤维与树脂的层间破坏和剥离强度相对较差，即层间剪切性能相对较差。申请人从蜂窝板模型中蜂窝芯材主要承载横向剪切力的原理中受到启发，采用磁场取向Fe3O4修饰的氧化石墨烯来增强碳纤维/环氧复合材料的层间剪切性能。本项目将系统研究磁场强度、树脂黏度、复合工艺等参数对于复合材料微观结构和性能的影响，确定磁场导向氧化石墨烯增强碳纤维复合材料的制备技术。通过对氧化石墨烯在复合材料中的取向状态、分散情况,复合材料中碳纤维和树脂的界面结合情况等微观结构进行分析，探索在磁场导向作用下，取向的氧化石墨烯对于碳纤维复合材料的增强机理。

碳纤维/环氧复合材料因具有比强度和比刚度高，抗疲劳断裂性能好，耐腐蚀，结构尺寸稳定性好等的优点，而被广泛应用于汽车、航空航天等高科技领域。但是碳纤维复合材料在厚度方向的强度相对较弱，例如，纤维与树脂的层间破坏和剥离强度相对较差，即层间剪切性能相对较差。本项目从蜂窝板模型中蜂窝芯材主要承载横向剪切力的原理中受到启发，采用磁场取向Fe3O4修饰的氧化石墨烯来增强碳纤维/环氧复合材料的层间剪切性能。本项目系统研究了磁场强度、树脂黏度、复合工艺等参数对于复合材料微观结构和性能的影响，确定了磁场导向氧化石墨烯增强碳纤维复合材料的制备技术。通过对氧化石墨烯在复合材料中的取向状态、分散情况,复合材料中碳纤维和树脂的界面结合情况等微观结构进行分析，探索了在磁场导向作用下，取向的氧化石墨烯对于碳纤维复合材料的增强机理。结果表明：当取向的Fe3O4/氧化石墨烯的含量小于1.0 wt%时，随着含量的增加，复合材料的层间剪切强度得到了改善。取向Fe3O4/氧化石墨烯的最佳含量为1.0 wt%，此时复合材料的层间剪切强度比纯的碳纤维复合材料提高了40.8%。虽然取向过的复合材料在3.0 wt%含量时的层剪强度相较于1.0 wt%时出现了下降的情况，但仍明显优于未取向过的复合材料。当Fe3O4/氧化石墨烯的含量为0.3 wt%时，未取向的复合材料的层剪强度达到了峰值，为48.1 MPa。当含量高于0.3 wt%后，复合材料的层剪强度出现下降情况，随着Fe3O4/氧化石墨烯含量的增加，层间剪切强度越来越小。当添加量达到3.0 wt%时，未取向复合材料的层剪强度只有37.7 MPa，甚至低于不添加的。总之，磁场取向对磁性颗粒氧化石墨烯/碳纤维/环氧树脂复合材料的层间剪切性能有明显改善效果。磁场强度越大，取向增强效果越好。