高速列车铜基摩擦材料的成分设计研究进展

Research Progress on Composition Design of Cu-based Friction Materials forHigh-speed Trains

铜基摩擦材料因具有优异的导热、抗氧化、抗高温粘着、摩擦因数稳定和耐磨损等综合性能,广泛应用于高速列车制动系统中,是高速列车安全运行的保障。铜基摩擦材料是采用粉末冶金工艺制备的由金属与非金属组成的多元复合材料,可以通过对材料成分大范围内的调节,实现材料摩擦磨损性能的调控。然而,随着高速列车向高速高能载方向发展,摩擦材料需要承受强表面氧化、高热负荷和高载荷冲击的共同作用,铜基摩擦材料在服役过程中出现基体高温软化、石墨润滑相烧蚀、摩擦衰退、以及掉边角等问题。近年来研究者从材料成分和工艺出发,通过对基体组元的固溶、弥散强化提高基体强度,采取润滑组元的多元复合拓宽温度适应范围,选择金属或合金摩擦组元替代陶瓷摩擦组元以及陶瓷颗粒表面镀铜等方法改善界面结合提高剪切强度。本文系统总结了铜基摩擦材料的成分设计研究进展,分析了各组元成分、含量的变化和发展趋势,综述了基体组元、润滑组元、摩擦组元以及界面结构的调控对材料摩擦磨损性能的影响,最后提出构建材料成分-摩擦层-摩擦磨损性能之间关系,为铜基摩擦材料成分设计提供依据。

Cu-based friction materials are widely used in the braking system of high-speed trains owing to their excellent properties of thermal conductivity,oxidation resistance,high-temperature adhesive resistance,stable friction coefficient and wear resistance.Cu-based friction material is a metal and nonmetal made composite,which is prepared by powder metallurgy process.The friction and wear properties of the material can be improved by adjusting the composition in a wide range.However,with the development of high-speed trains towards high-speed and high-energy load,friction materials have to suffer the combination of strong surface oxidation,high thermal load and high load impact.Problems,such as matrix softening at high temperature,graphite lubricating phase ablating,friction decay and edge loss,occur during the service process of Cu-based friction materials.In recent years,researchers focus on the composition and preparation process.The strength of matrix is improved by solid solution and dispersion strengthening.Multiple compound lubrication components are adopted to broaden the range of temperature adaptation.Using metal or alloy friction components instead of ceramic or copper-plated ceramic particles can improve interface bonding and shear strength.This paper systematically summarizes the research progress on the composition of Cu-based friction materials.The variation and development trends of components and the contents of each component are analyzed.The influences of matrix component,lubrication component,friction component and interfacial structure on tribological properties of materials are reviewed.Finally,the relationships between composition,friction layer and tribological performance are proposed to provide a basis for the composition design of Cu-based friction materials.