【作者】 樊荣；

【导师】 许云华； 钟黎声；

【作者基本信息】 西安理工大学 ， 材料加工工程， 2022， 硕士

【摘要】 碳纤维/树脂复合材料是一类高性能的复合材料,具有高比强度、高比模量、耐疲劳等一系列的优异性能,已经在国民经济的各个领域如航空航天、体育器材等方面有着较为广泛的应用。碳纤维/树脂界面微区的组织与性能对碳纤维增强树脂基复合材料的结构强度和功能性的实现起着非常关键的作用。但是,碳纤维表面取向一致的碳原子堆叠层,对外表现出化学惰性和非极性,加之碳纤维的表面具有光滑、疏水、吸附性差等特性,对碳纤维/树脂复合材料的组织和性能十分不利。若直接将碳纤维与树脂进行复合,界面极差的粘结性完全不能满足人们对碳纤维增强树脂基复合材料结构强度和功能性的需求,如何实现碳纤维与树脂在界面微区的化学相容或物理相容是当前复合材料设计与制备的研究热点和难点。本工作利用两种不同的物理制备工艺,即铌粉包覆“一步法”以及多弧离子镀-原位反应“两步法”在碳纤维表面制备了碳化铌(NbC)硬质颗粒点,将改性后的碳纤维与环氧树脂EL2进行复合制得复合材料,并通过拉伸、弯曲等性能测试对碳纤维/树脂复合材料的界面结合效果进行表征。针对碳纤维表面NbC硬质颗粒点的组织形貌、相转变以及与树脂复合后复合材料的力学性能展开研究。研究结果表明:(1)通过多弧离子镀-原位反应“两步法”在碳纤维表面制备碳化铌,并以多弧离子镀的镀膜时间为变量进行实验,东丽系列碳纤维经原位反应后留在表面的硬质点数量较国产台塑碳纤维更多,粘接效果更好;东丽T700无胶碳纤维与T700碳纤维原丝相比,与金属铌原子的机械锚定效果更好,结合更加牢固;(2)通过包覆改性“一步法”在碳纤维表面制备碳化铌,以机械混合的时间与原位反应的时间为变量进行实验,机械混合能有效地分散金属粉末,使粉末回归到非团聚状态,机械混合的效果和原位保温时间的长短均会影响碳纤维表面碳化物的生成效果。(3)碳化铌硬质点的加入会使外加载荷的分布更为均匀,会形成空穴、裂纹偏转以及钉扎等增强机制,使得复合材料的综合力学性能得到相应提升,能显著改善碳纤维增强树脂复合材料的力学性能,尤其是韧性。经“一步法”包覆改性的碳纤维与环氧树脂EL2复合后的韧性在碳纤维原丝的基础上提升了 26.7%;经多弧离子镀-原位反应“两步法”改性改性的碳纤维与环氧树脂EL2复合后的韧性与原丝相比,其韧性提高了 190%。(4)经铌粉包覆“一步法”改性的碳纤维与树脂复合后其综合性能较好,在拉伸和弯曲性能中均表现的较平衡,同时其成本较低,经济适用性强;而经多弧离子镀-原位反应“两步法”改性的碳纤维与树脂复合后其增韧效果非常好,同时其实验成本高昂,对长丝改性后还需剪短至短纤维与树脂进行复合,在具体的工程应用中较难批量化生产,但对物理法改性碳纤维与树脂复合材料的界面结合提供了比较新颖的实现途径。更多还原

【Abstract】 Carbon fiber/resin composite materials are a class of high-performance composite materials,with high specific strength,high specific modulus,fatigue resistance and a series of excellent properties,has been in various fields of the national economy such as aerospace,sports equipment and other aspects have a wide range of applications.The microstructure and properties of the carbon fiber/resin interface microregion play a key role in the structural strength and functionality of carbon fiber-reinforced resin matrix composites.However,the carbon atom stack with the same surface orientation of carbon fiber shows chemical inertness and non-polarity to the outside world,and the surface of carbon fiber has the characteristics of smoothness,hydrophobicity and poor adsorption,which is very unfavorable to the microstructure and properties of carbon fiber/resin composites.If the carbon fiber is directly recombined with the resin,the extremely poor adhesion of the interface can not meet people’s needs for the structural strength and functionality of the carbon fiber reinforced resin matrix composite,and how to achieve the chemical compatibility or physical compatibility of carbon fiber and resin in the interface microregion is the current research hotspot and difficulty of composite material design and preparation.In this work,two different physical preparation processes,namely niobium powder coating "one-step method" and multi-arc ion plating-in-situ reaction "two-step method",niobium carbide(NbC)hard particle points were prepared on the surface of carbon fibers,and the modified carbon fibers were composited with epoxy resin EL2 to obtain composite materials,and the interface binding effect of carbon fiber/resin composites was characterized by tensile and bending performance tests.The micromorphology,phase transition and mechanical properties of composite materials after composite with resin composites on the surface of carbon fibers are studied.The findings suggest:(1)By the "two-step method" of multi-arc ion plating-in situ reaction,niobium carbide was prepared on the surface of carbon fiber,and the coating time of multi-arc ion plating was used as a variable for experiments,and the number of hard points left on the surface after the in situ as a variable for experiments,and the number of hard points left on the surface after the in situ reaction of Toray series carbon fibers was more than that of domestic Formosa Plastics carbon fibers,and the bonding effect was better;Compared with the T700 carbon fiber filament of T700,the mechanical anchoring effect of niobium atoms was better and the binding was more firm;(2)Through the coating modification "one-step method" to prepare niobium carbide on the surface of carbon fiber,the time of mechanical mixing and the time of in situ reaction are experimented with variable,mechanical mixing can effectively disperse the metal powder,so that the powder returns to the non-agglomeration state,the effect of mechanical mixing and the length of in-situ insulation time will affect the formation effect of carbides on the surface of carbon fiber.(3)The addition of niobium carbide hard particles will make the distribution of the applied load more uniform,and will form enhancement mechanisms such as holes,crack deflection and nailing,so that the comprehensive mechanical properties of the composite materials can be improved accordingly,and the mechanical properties of carbon fiber reinforced resin composites,especially the toughness,can be significantly improved.The toughness of the carbon fiber coated and modified with EP2 after the "one-step method" was increased by 26.7%on the basis of the carbon fiber filament,and the toughness of the carbon fiber modified by the multi-arc ion plating-in-situ reaction "two-step method" was increased by 190%compared with the protofilament after the composite of the carbon fiber and the epoxy resin EL2.(4)After the niobium powder coating "one-step method" modified carbon fiber and resin composite,its comprehensive performance is better,in the tensile and bending properties are more balanced,while its cost is lower,the economic applicability is strong;and the multi-arc ion plating-in situ reaction "two-step method" modified carbon fiber and resin after the combination of its toughening effect is very good,at the same time its experimental cost is high,the filament modification also needs to be cut short to short fiber and resin composite,in specific engineering applications is difficult to mass production,However,the interface combination of physically modified carbon fiber and resin composite materials provides a relatively novel way to achieve it.更多还原