铜基受电弓滑板材料的制备工艺及性能研究

发布时间：2018-04-04 22:06

  本文选题：铜基受电弓滑板　切入点：粉末冶金　出处：《合肥工业大学》2017年硕士论文

【摘要】：城市轨道交通和山区低速重载电力机车运输是目前铁路运输中相当重要的两个板块,对电力机车的需求量非常大。而铜基受电弓滑板是应用于电力机车的重要受电元器件,其消耗量也越来越大,但目前国内技术还不够成熟,需要大量的依赖进口。为了打破国外垄断,加速铜基受电弓滑板的国产化是当前铁路运输业中一项非常重要的任务。本文主要研究了粉末冶金法制备铜基受电弓滑板材料工艺,探讨了不同种类润滑剂对材料产生的影响,主要分析了冷压行为和烧结行为等,对烧结后材料的物相组成、微观形貌、力学性能以及摩擦磨损性能结果进行了研究分析。同时研究了时效温度与时间对铜合金的显微组织及物理、力学和摩擦磨损等性能的影响,探究了该铜合金的时效特性。本研究对于开发具有自主知识产权的铜基粉末冶金受电弓滑板提供了技术与理论指导,取得的主要成果如下:(1)压制规律:在铜合金混合粉末冷压成形过程中,压坯密度随着压制压力的增大而不断提高,但压坯密度的提高速率随着压制压力的增大而逐渐变缓。铜合金混合粉末的压制过程符合四种经典压制方程的描述,尤以黄培云方程最为近似。经黄培云方程计算后可得,铜合金混合粉末的最小二乘法相关系数R值为0.997980,最接近于1,其硬化指数m为2.26313,压制模数M为6.05885MPa。(2)制备工艺:在高温烧结过程中,烧结体密度随着烧结温度的升高和烧结时间的延长,呈先增大后减小的趋势,得出合适的烧结温度为900℃,烧结时间为2h。通过对比不同含量的石墨、Cu2S和MoS2三种润滑剂对铜基受电弓滑板材料性能的影响,得出石墨相对于其他两种润滑剂,最宜作为铜基受电弓滑板材料的润滑剂。当石墨含量为2%时,铜基受电弓滑板综合性能最好,其电阻率为0.22μΩ·m,冲击韧性为34.2J/cm~2,硬度HB为75。(3)时效处理:将自主研发的铜基受电弓滑板材料,在830℃下固溶2h并水淬处理,然后在450~600℃下经过1~4h时效处理。通过对不同时效温度和时间下材料硬度、电阻率、冲击韧性和抗拉强度等性能的测试,以及微观组织与物相组成的观察与分析,研究铜基受电弓滑板材料的时效处理行为。结果表明:随时效时间延长,铜基滑板材料的硬度、冲击韧性和拉伸强度都先提高后下降,电阻率先下降后略有升高;随时效温度升高,材料的各项性能均先提高后下降。时效处理前后材料断裂均以塑性断裂的方式进行,时效处理后的冲击韧性更大。在500℃下时效处理3h后,主要物相仍是α-铜和石墨,并产生纳米级的六方Cu10Sn3析出相,对基体产生强化作用,从而提高材料的各项性能。材料的电阻率为0.147μΩ?m,硬度HB为89,抗拉强度为355.68MPa,冲击韧性为47.1J/cm~2,摩擦因数为0.189,基本符合我国对铜基受电弓滑板材料的使用要求,综合性能接近国外水平。
[Abstract]:Urban rail transit and low-speed and heavy-haul electric locomotive transportation in mountainous area are two very important plates in railway transportation at present, and the demand for electric locomotives is very large.The copper-based pantograph slide plate is an important component used in electric locomotives, and its consumption is increasing. However, the domestic technology is not mature enough and needs a large amount of import.In order to break the foreign monopoly and accelerate the localization of copper-based pantograph slide plate is a very important task in the current railway transportation industry.In this paper, the preparation process of copper-based pantograph slide plate by powder metallurgy is studied, and the influence of different kinds of lubricant on the material is discussed. The cold pressing behavior and sintering behavior are mainly analyzed, and the phase composition of the sintered material is analyzed.The results of microstructure, mechanical properties and friction and wear properties were studied and analyzed.The effects of aging temperature and time on the microstructure, physical, mechanical, friction and wear properties of the copper alloy were also studied.This study provides technical and theoretical guidance for the development of copper-based powder metallurgy pantograph slide plate with independent intellectual property rights. The main results obtained are as follows: in the process of copper alloy mixed powder cold pressing,The compaction density increases with the increase of pressing pressure, but the increasing rate of billet density decreases with the increase of pressing pressure.The compaction process of copper alloy mixed powder accords with the description of four classical pressing equations, especially Huang Peiyun equation.According to Huang Peiyun equation, the correlation coefficient R value of the least square method is 0.997980, which is the closest to 1. The hardening index m is 2.26313, and the pressing modulus M is 6.05885MPa.t2).With the increase of sintering temperature and the prolongation of sintering time, the sintered bulk density increased first and then decreased. The suitable sintering temperature was 900 鈩，

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