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Title:: Progress in Powder Metallurgical Brake Materials for HighSpeed Trains

Author(s):: YAO Pingping; XIAO Yelong; ZHANG Zhongyi; ZHOU Haibin; GONG Taimin; ZHAO Lin; DENG Minwen; State Key Laboratory of Powder Metallurgy，Central South University，Changsha 410083，China

Keywords:: highspeed train; brake materials; powder metallurgy; research progress; tribological properties

Abstract:: To meet the demands of highspeed trains that become faster, safer, more comfortable and ecofriendly, the brake materials for highspeed trains should possess the characteristics of the predictable friction coefficient, satisfactory wear resistance, high heat resistance and thermal fatigue resistance, sufficient mechanical performance, low aggressivity against the brake disc, and environmental friendliness. Due to their attractive properties, powder metallurgical materials are top choices as brake materials for highspeed trains with the maximum speed of 300 km/h and above. Research progress on the materials design, preparative technique, tribological properties, and performance assessment of powder metallurgical brake materials for highspeed trains in recent years were summarized. Firstly, the fundamental research on metal matrix, lubricant component, and friction component, and the trends on environmental friendliness and simplification of components added to the material were elaborated. Secondly, the effects of process parameters on the frictional properties were discussed, and the progress in preparative technique was described. Thirdly, the influences of the braking conditions on the tribological properties were analyzed, and the adaptability of brake pads/disc was introduced. Finally, the braking performance evaluation and prediction were demonstrated, and the latest research progress in the friction and wear mechanism was reviewed.