Internal Interface Modification And Mechanical And Electrical Performance Optimisation Method Of Pantograph Slide

The pantograph slide is a key collecting element for high-speed trains to obtain energy,and its good service performance is the basis for ensuring safe and reliable train operation.The pantograph slide is widely used with carbon/copper composite materials,but due to the poor wettability of the two phases of carbon and copper,the interface bond between them is weak,which seriously restricts the mechanical and electrical properties of the material,making the pantograph slide prone to fracture and fall off when subjected to high-speed impact,leading to the risk of power supply interruption.Therefore,it is important to solve the problem of weak interfacial bonding within the pantograph slide and improve its mechanical and electrical impact stability to ensure reliable electrical energy transmission in the pantograph catenary system.From the root of the problem of weak carbon-copper micro-interface bonding,an in situ reaction to form a tungsten carbide interlayer to enhance the wettability of the carbon/copper interface was developed.A finite element model of the carbon/copper two-phase flow was developed to analyse the promoting effect of the interlayer on the interfacial wettability,and the immersion kinetic properties of the copper melt in the porous carbon matrix were systematically investigated.The riveted interfacial structure and laminar interfacial structure are formed by designing inside the composite material,thus effectively reducing the void defects inside the material and significantly improving the mechanical and electrical properties as well as the stability of the composite material under high temperature impact.The constructed tungsten carbide interlayer reduces the carbon/copper contact angle from 138° before the modification to 23°.The prepared composite formed a new Cu/WC/C interface internally,and the mechanical interlocking bond between carbon/copper was converted to a chemical bonding,which greatly improved the bonding force.The theoretical analysis demonstrates that the flow of the copper melt in the carbon matrix is close to a turbulent state and that the tungsten carbide effectively facilitates the transfer of the replacement pressure,reducing the capillary resistance during the infiltration process and significantly increasing the saturation of the copper melt.The experiments show that the particle-doped modified carbon/copper composite formed a riveted structural interface inside the composite,and the compressive strength,flexural strength and electrical conductivity of the composite increased by nearly 42.1%,20.3% and 45.4% respectively compared to the unmodified composite.The electromechanical properties of both modified composites far exceeded the requirements of the IEC international electro-carbon industry standard.Finally,the thermal shock damage characteristics of the composites were investigated through thermal cyclic impact tests,and it was found that the prepared composites were able to maintain good stability under high temperature impact.This study provides new ideas and methods for the development of high-performance pantograph slide materials,and can also provide theoretical and technical references for the development of new electrically and thermally conductive materials with high-temperature stability.