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Crack Propagation And Microstructural Transformation On The Friction Surface Of A High-Speed Railway Brake Disc, Zhizhong Wang, Jianmin Han, Joseph P. Domblesky, Zhiqiang Li, Xinguang Fan, Xiaolong Liu

Mechanical Engineering Faculty Research and Publications

While brake disc wear represents a significant problem in high-speed rail systems, the progressive development of fatigue cracks during successive braking cycles also plays a great role in braking integrity. The modified microstructure consisting of a white etching layer (WEL) containing nanosized ferrite was observed on the friction surface of worn brake discs. In order to analyze how sequential thermal and mechanical stress affected crack propagation and microstructure evolution in brake discs, successive braking cycles were simulated on a full-scale braking bench test rig. Crack initiation and propagation mechanisms were proposed based on the experimental results, i.e., (i) occurrence of …