Research On The Preparation And Performance Of Pantograph Slide Plates

Copper/graphite self-lubricating composites with metallic matrix are important new function materials. With both the characteristic of conducting electricity and heat and function of wearable and lubricate, and also the capability of high mechanical rigidity, copper-graphite can be widely used as pantograph slider, brush, and electrical contact materials in the new type function materials fileds.Because the wetting angle between copper and graphite reached 140°at 1100℃, graphite is hard to disperse in copper and easy to initiate aliquation. Copper/graphite self-lubricating composites with metallic matrix which is produced in traditional methods couldn't perform well because there is only mechanical mixing between them, thus the interfacial bond strength is low. In this paper, the research is to improve the technology in this way, which first plate copper film on the graphite surface, then produce the composite by adding copper powder. The interface has been changed into metal-metal from graphite -metal, which ameliorates the wetting quantity and combination at experiments conditions above.We studied the influence of the concentration of CuSO4·5H2O,the content of ice acetic acid, the reaction temperature and time on copper plating of graphite powder by the single factor experiment.And we got the best condition of copper plating on graphite power:the content of CuSO4·5H2O is 60g/L,that of ice acetic acid is 16ml/L, the reaction temperature is 35℃and the reaction time is 40min.Under this reaction condition, we get the copper plating graphite powder with close and even layer.Based on using bluestone as main solute and zinc powder as reductant, we analyzed the influence of the preparation processes on the performance of materials in this paper. This subject study the influence of grain size of graphite powder, content of graphite, compacting pressure and sintering temperature on mechanical character. The conclusion is that the composites properties is greatly improved under the optimal technology that the grain size of graphite powder is 61-76μm, content of graphite is 15%, the pressure is 250-300MPa, the sintering temperature is 850-900℃and the time of heat preservation is 5h.Using the preparation in this paper, we can get the Copper/graphite composites with metallic whose rigidity is 52-58HB, conductivity is 3.163×107S/m and impact ductility is 3.43J·cm-2. Compared with metallized carbon contact strip, the performance of electric conduction has a obvious increasing. Abrasion is one of the most important factors that restricted the performance and longevity of pantograph slide plates. The wear and teat examination of the sample was carried out under the simulative practical work condition. And we get that the friction coefficient of the sample is 0.08 under the condition of slide plate's practical work pressure.