Study On Modification And Performance Effect Of Carbon Nanotube Reinforced Carbon Graphite Materials

The high-speed,high-density,and large-capacity development of railway transportation makes the current-receiving parts of electric locomotives face severe tests.During the operation of the train,the pantograph sliding plate not only has to friction and slide with the contact line at high speed,but also face the problems of impact and collision,arc ablation and harsh environment.Therefore,the pantograph slide material needs to meet the comprehensive performance requirements of high strength,high conductivity,and high wear resistance.However,as a multi-phase,multi-component,structural composite material,the carbon-graphite material for pure carbon skateboards currently in service has internal defects such as cracks and pores affected by the nature of the raw materials and the preparation process,showing heterogeneous characteristics.In practical applications,there are problems such as low mechanical strength and short service life.Therefore,improving the mechanical properties of carbon graphite materials from the perspective of matrix congenital defects control will be the key to the optimization and upgrading of the service performance of pure carbon slide materials.In this paper,pitch-based carbon-graphite materials are used as the research object.Aiming at the problem that heterogeneous carbon-graphite materials are difficult to achieve the advantages of structure-function integration,carbon nanotubes with good compatibility with the carbon matrix are selected as the control material for structural defects.From the perspective of improving the dispersibility of carbon nanotubes in the matrix and the interface bonding,the dispersion and introduction method of "carbon nanotubes modified with oleic acid-coal pitch melt blending-composite preparation" was designed.With the help of carbon nanotubes modified with oleic acid,they have good dispersibility in kerosene and the "similar compatibility" of the pitch raw materials and kerosene.The carbon nanotubes are first melted and blended with the pitch raw materials.Evenly dispersed in the binder pitch,and then with the help of the binder pitch to coat and bond the raw material particles during the preparation process,a carbon nanotube-reinforced three-dimensional framework network structure is constructed between the various phases of the matrix.Through the characterization and analysis of the dispersion of carbon nanotubes and the performance of the material at each stage of the preparation of carbon graphite materials,it is found that this method can effectively disperse the carbon nanotubes in the matrix.When the modified content of carbon nanotubes is 0.1%,The flexural strength of the one-time baking and copper immersion materials increased by 32.1% and 31.4%,respectively,the wear rate of the material decreased by 39.4%,and the electrical conductivity of the material was less affected.At the same time,the article also clarified the effect mechanism of carbon nanotubes on the defect regulation and performance of the material.The research results of this paper can provide theoretical basis and scientific guidance for the research and design of high-performance carbon skateboard materials.