Friction control during automotive braking: Experimental observations and simulation at nanometre scale
Friction control during automotive braking: Experimental observations and simulation at nanometre scale
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汽车制动过程中的摩擦控制：纳米尺度的实验观察和模拟
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
A. Dmitriev
中科院分区：
文献类型：
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作者：
W. Österle;Heinz Kloß;A. Dmitriev
用分析透射电镜研究了刹车片和刹车盘摩擦膜的结构和成分。所观察到的膜仅为100-500 nm厚，并且包括与少量其他垫成分混合的氧化铁的纳米晶微结构。基于可移动元胞自动机的模型被应用于模拟在垫/盘界面的情况。实验结果表明，在旋转盘和固定垫之间存在着准液相层、速度调节和纳米粒子的机械混合等特征。此外，该模型揭示了不同的层组合物的摩擦系数的演变。摩擦膜的纳米结构对于摩擦力稳定和消除波动非常重要。模拟结果表明，10%的固体润滑剂的体积分数是必要的良好的制动性能。
The structure and composition of friction films on brake pads and rotors were studied by analytical transmission electron microscopy. The observed films were only 100–500 nm thick and comprised a nanocrystalline microstructure of iron oxide mixed with minor amounts of other pad constituents. A model based on movable cellular automata was applied to simulate the situation at the pad/disc interface. The following features could be shown clearly: formation of a quasi liquid layer, velocity accommodation between the rotating disc and the fixed pad and mechanical mixing of nanoparticles from pad and disc. Furthermore, the model revealed the evolution of the coefficient of friction for different layer compositions. The nanostructure of the friction film was very important with respect to friction force stabilisation and elimination of fluctuations. The simulation results suggest that a volume fraction of 10% of a solid lubricant is essential for good brake performance.