【作者】 张婧琳；

【导师】 孙乐民；

【作者基本信息】 河南科技大学 ， 材料加工工程， 2010， 硕士

【摘要】 本文以紫铜/铬青铜为摩擦副,模拟电力机车接触网中受电弓滑板和接触网导线的服役条件,在自制的HST-100销盘式摩擦磨损试验机上进行载流摩擦学特性研究。采用正交试验方法探讨载流条件下电流、载荷和速度这三个主要影响因素对载流摩擦副摩擦磨损性能的影响程度,对比研究了该摩擦副在有无电流条件下的摩擦磨损特性;使用单因素试验方法考察了载流条件下摩擦磨损条件、摩擦磨损性能、电弧能量与销试样表面温度之间的关系。利用扫描电子显微镜(SEM)、能谱仪(EDS)对材料的磨损表面进行观察,探讨了不同参数条件下的载流摩擦磨损机制。正交试验表明,电流是影响载流摩擦副摩擦磨损性能的最显著的因素,载荷和速度次之。与无电流相比,载流条件下在同载荷不同速度时摩擦系数呈减小趋势,磨损率较大;同速度不同载荷时摩擦系数也减小,磨损率较大;在不同电流条件下,随着电流的增大,摩擦系数逐渐减小,而磨损率逐渐增大。不同参数条件下的销试样摩擦过程中表面温度变化是不一样的,但都要经过一个先急剧增大,然后平稳的过程。并且不同参数下销试样传热达到稳态时的表面温度值也是不一样的。在同载荷同速度不同电流条件下,销试样表面温度增大时摩擦系数降低,磨损率增大;在同电流同速度不同载荷条件下,销试样表面温度的变化与摩擦副的摩擦磨损性能之间关系较为复杂,并在载荷为0.26MPa时销试样表面温度达到最大值;在同电流同载荷不同速度条件下,销试样表面温度增大时摩擦系数降低,磨损率增大。同时试验表明电弧能量与销试样表面温度有密切的关系,电弧能量越大,销试样表面稳态温度值也越大。对磨损面微观分析表明:无电流条件下,销试样磨损机制主要表现为粘着磨损,而载流条件下,销试样磨损表面有大量的粘着和塑性流动痕迹,并且可以看到有熔化,烧蚀坑的痕迹和由于热应力导致的裂痕,同时由能谱图可以得到磨损表面有氧的生成,说明摩擦表面生成了氧化物。因此其主要磨损机制为粘着磨损、氧化磨损和电弧烧蚀。更多还原

【Abstract】 The test was carried out on the HST-100 pin-on-disc tribo-tester with Cu/QCr0.5 couples, which simulated working conditions of the pantograph-wire system used in electric railway. The effects of current, loading and speed on friction and wear properties were investigated by orthogonal experiment. The differences in the friction and wear properties with and without current were studied. Single-factor tests were conducted to investigate the relationship between the pin surface temperature and the friction and wear properties, arc energy. With the help of SEM and EDS, the morphologies of worn surface of the pin were examined, in order to study the tribological mechanism under different parameters.According to the orthogonal experiment, the current is the most notable factor affecting the friction and wear properties of this couple under the conditions of electrical current, and followed by load and speed. Compared with non-current conditions, the friction coefficient declined and the wear rate of the couple was much higher at the same loading and different velocities, and in the same under the conditions of the same velocities and different loadings. What’s more, with the increasing current, the friction coefficient decreased, while the wear rate was gradually increasing.The temperaturverlauf of the pin specimens isn’t the same under different parameters. But there would be a sharp increase in the first, and then gently change. And the steady-state surface temperature value is not the same under different parameters. At the same loading and velocity, the pin surface temperature increased, and so done the wear rate, while the friction coefficient decreased. At the same current and velocity, the relationship between temperaturverlauf and the friction and wear properties is more complex, and the sample surface temperature reached the maximum at the loading of 0.26MPa. Under the conditions of the same current and loading, as the pin surface temperature increased, the friction coefficient, but the wear rate increased. Also, arc energy is closely related to the sample surface temperaturverlauf, which can be concluded from the test.Combination of the SEM images of the worn surface, adhesive wear was the dominant mechanism without current. But under the current conditions, there was a large number of adhesion wear and plastic flow traces on the sliding surfaces. And a few melting or arc pit traces can be observed. And the cracks can be also observed due to the role of thermal stress generated in Instantaneous and concentration high temperature of arc. And the EDS of the worn surface indicated that oxidation took place in the friction process. In a word, adhesive wear, oxidative wear and electrical wear were the dominant mechanism.更多还原