A review of tribological behavior of brake pads for high-speed train

As a key safety component of high-speed rail systems, brake pads fundamentally determine braking efficiency, operational reliability, and component life. As train speeds rise and the operating environment's growing complexity, studying the tribological properties of brake interfaces has become a major engineering challenge. In terms of tribological behavior, brake pads’ wear performance, brake noise, and thermal distribution at the braking interface are the focus of the study. To better reveal the current research status of brake pad tribological behavior, the influencing factors of brake pad wear performance are first analyzed, and the effects of different materials, braking conditions, and service environment on brake pad wear performance are discussed in detail. Secondly, the correlation between brake noise and the tribological behavior of brake pads is analyzed from the aspects of friction self-excited vibration, interface wear characteristics, and thermal distribution inhomogeneity. In addition, the complex interaction relationship between the thermal distribution of the braking interface and the tribological behavior of the brake pads is elaborated to analyze the influence of the thermal distribution of the braking interface on the tribological behavior of the brake pads. Finally, the progress and shortcomings of the current study are summarized, and future research directions are proposed, including the development of new materials, the innovation of preparation process and the study of tribological behavior under the coupling of multi-conditions, to provide relevant references for the improvement of the overall performance and reliability of the brake pads of high-speed trains.