Fabrication And Properties Of Pantograph Slider Material By P/M Process

With the rapid development of high-speed railway and urban rail transit, China has entered the high-speed era. As an important take-power component to high-speed railway and urban rail transit, the pantograph, which is mainly dependent on import, is experiencing a huge demand in consumption, so it is time for us to solve the urgent problem of pantograph localization. This paper mainly focused on the exploration and analysis to the component designing and the process of the copper-based and carbon-based pantographs. By comparing the resistivity, strength, friction and wear performance of the pantograph, the best formula and process were determined, The pantographs were compared with the national standards and import ones.A new type of copper-based pantograph, which was made up of copper, graphite, aluminum, nickel and so on, was successfully prepared by sintering the specimen in an atmosphere of N2 and H2 gas mixture. The effect of graphite content on electrical resistivity, impact toughness, hardness, friction coefficient and wear performance and the effect of nickel content on impact toughness, hardness were studied. The toughening and strengthening effect of solid solution and dispersed phase were also analyzed. As the results showed, the graphite had a significant influence on the density of copper-based pantograph. With the increasing of graphite content, the electrical resistivity improved, while the impact toughness and the friction coefficient decreased. What’s more, the anti-friction and wear performance became better. It should be noticed that the graphite had an opposite effect on the properties of copper-based pantograph if the content exceeded a certain value. With the increasing of the nickel content, the hardness and the impact toughness of pantograph were also improved. When the content of graphite and nickel were both 3%, the performance was achieved with electrical resistivity 0.22μΩ·m, hardness HB60, impact toughness 7.1 J/cm2, friction coefficient 0.19, which could meet the basic requirements of national standards.Carbon-based pantograph is made of graphite, pitch, petroleum coke, carbon black and carbon fiber, which is obtained by mixing, pressing, roasting, and resin-impregnated. The effect of graphitization temperature on resistivity, density and flexural strength was studied; the effect of graphite content on resistivity, flexural strength, friction and wear properties and the effect of pitch content on resistivity and flexural strength were studied; the effect of resin-impregnated was also studied. As the results showed, with the increasing of pitch content, the density increased first, then decreased and the resistance increased; with the increasing of graphite content, the resistance decreased, while the flexural strength and density both increased. However, at higher graphite content, the increase slowed down, and the friction coefficient and wear properties became better. When the value exceeded 40%, the graphite content had a little effect on the properties. The performance got better after curing resin impregnation, the density increased to 0.1g/cm3, the flexural strength improved to 10MPa and the resistivity changed a little. When the graphite content was 40% and the pitch content was 25%, the performance was achieved with the density 1.7g/cm3, resistivity 20μΩ·m, flexural strength 38Mpa, which could meet the basic requirements of national standards, and was close to the imported pantograph.