Study On The Method Of Improving The Conductivity Of Metal Impregnated Carbon Based Pantograph Strip Materials

Copper-impregnated carbon pantograph strip material has high mechanical strength,excellent electrical conductivity,self-lubricity and good wear resistance,so this kind of pantograph strip is widely used in urban rail transit and high-speed railway transportation.However,as the train speed continues to increase,the requirements for the current drawn by the pantograph and the net are getting higher and higher.Research has found that the copper phase continuity in the copper-immersed carbon slide plate currently produced is not good,and there is no good impregnation channel.Poor connectivity of internal stomata.At present,the distribution of the copper phase in the pantograph slide is mostly through direct embedding of the prepared copper mesh or direct impregnation of the prepared copper network with a binder such as resin,although the copper phase is connected to make the material conductive The performance is improved,but there are problems such as more carbon phase pores and excessive copper phase addition ratio.Therefore,in order to solve the problem of poor continuity of the copper phase inside the copper immersion carbon slide,this paper proposes a new type of copper immersion carbon slide structure,in which the copper phase is randomly distributed in a continuous filament structure,and the hole is first made and then the The impregnation method realizes the connection of the copper phase,and reduces the pores existing in the carbon phase,making the matrix structure more dense.On the structural optimization of the simulation model,the work before material preparation mainly includes the selection of pore formers and the structural optimization of simulation models.In the selection of pore formers,this experiment studies the requirements for pore formers at different stages of the preparation process of copper-impregnated carbon materials,and proposes the basis for the selection of pore formers.Mainly from the basic properties of the pore former,the requirements for the structure of the pore former during the cold pressing of the composite material,and the effect of reducing the asphalt flow of the binder on the pore former structure during the high-temperature roasting stage.Nine basis for the selection of porogen,and thus determine the type of pore former as PMMA.This article is based on the test and measurement methods of electric carbon products in JB/T 8133《Testing Methods for the Physical and Chemical Properties of Electric Carbon Products》.The test parameters are determined by the force analysis of the immersion droplets,and the simulation result data is processed.Found the relationship between the shape of the copper phase structure and the resistivity of the copper-immersed carbon material,which can generally be divided into three stages for distribution.In the first stage,the composite material resistivity is mainly affected by variables,and the second The influence of the three stage variables on the resistivity of the composite material is reduced.The third stage variable no longer becomes the main factor of the resistivity change of the composite material.When the fixed conditions of the copper phase structure change,the second stage will have different degrees of bias.shift.Through the above research,it is found that when the copper phase volume ratio in the copper-immersed carbon material is3%,the length of the copper wire is 6mm,and the radius is 0.1mm,this solution can effectively reduce the resistivity of the copper-immersed carbon material.After various processes,a new type of copper immersion carbon material was prepared.The density,resistivity,compressive strength,flexural strength and wear resistance of the material were tested.The microstructure of the material was studied,and the new type of copper immersion The electrical resistivity test of the carbon slide material found that the actual measurement results are consistent with the simulation results.The electrical conductivity of the copper immersion carbon material can be improved.When the diameter of the pore former is 0.25mm,the length is 0.6cm,and the volume accounts for When the ratio is 3%,the resistivity of the composite material gradually stabilizes with the increase of the length of the pore-forming agent,and the resistivity is 3.13μΩ*m.Compared with the case where the pore-forming material is not added,the resistivity is reduced by about 30%.The continuous copper phase structure in the new copper-impregnated carbon material makes the pantograph strip material less likely to fall off,break and other safety hazards.Therefore,this special structure of the copper-impregnated carbon pantograph strip has higher safety and reliability,and improves the service performance of the pantograph strip..Through the current-carrying friction experiment,it is found that the construction of the copper network structure in the copper-immersed carbon slide plate can effectively reduce the friction coefficient and the amount of wear between the friction pairs.When the diameter of the pore former is 0.25mm,the length is 0.6cm,and the volume ratio is 3%,the friction coefficient of the composite material is about 0.18,and the amount of wear is65g/10~4km.