列车制动用Cu基粉末闸片材料摩擦磨损性能分析

列车的制动性能与闸片材料的摩擦磨损性能关系密切,在MM-1000Ⅱ型摩擦试验机上测试了自制的Cu基粉末列车闸片材料在不同制动速度下的摩擦磨损特性。结果表明:随着制动速度的增大,摩擦表面的微凸起遭到破坏,摩擦因数随之降低,磨损量增加;在材料接触表面产生大量的摩擦热,造成基体软化,减小了基体对材料中SiO_2等硬质颗粒的夹持能力。摩擦因数和稳定系数均随制动速度增加而降低;而摩擦温度和磨损量随制动速度增加而提高,尤其是在制动速度大于8 r/s时,摩擦表面温度上升,造成基体软化,硬质颗粒脱落,加速了材料的摩擦磨损。为列车制动用Cu基粉末闸片材料摩擦磨损性能的研究提供了理论基础。

Analysis of friction and wear properties of copper-based powder brake linings for train braking

The braking performance of the train is closely related to the friction and wear performance of the brake linings material.The friction and wear characteristics of self made copper based powder train brake material at different braking speeds were tested on a MM-1000Ⅱ friction tester.The results show that with the increase of braking speed,the micro bulge on the friction surface is destroyed,the friction coefficient decreases and the wear loss increases.A large amount of friction heat is generated on the contact surface of the material,which results in the softening of the matrix and reduces the clamping ability of the matrix to the hard particles such as SiO2.The friction coefficient and stability coefficient decrease with the increasing braking speed;while the friction temperature and the wear loss increase with the increasing braking speed,especially when the braking speed is greater than 8 r/s,the rising friction surface temperature leads to the matrix softening and the hard particles falling,thus accelerates the friction and wear of materials.It provides a theoretical basis for the study on the friction and wear properties of copper based powder brake linings for train braking.