Abstract:
In this study, a serviced brake pad on CRH380A high-speed train was collected, and the wear features and corresponding wear mechanisms of the brake pad were analyzed by different micro-analysis methods. Exfoliation and cracks were found to be the main wear features of the brake pad. Combining the microscopic analysis of the worn surface and the finite element analysis of stress distribution at different friction blocks, the wear mechanisms of the two kinds of wear features above were clarified. The results show that the exfoliation of the friction block was mainly caused by the micropores formed during material processing, and the difference of the material components' hardness and wear resistance. The contact stress concentrated on the leading edge of brake pad may be one of the leading reasons for the nonuniform wear. In addition, stress concentration can be found near the center hole of the friction block, which made the initiation of cracks much easy around the edge of the hole. The micropores formed during their material processing and the insufficient bonding strength between different components also led to the initiation and propagation of cracks.