Abstract:In order to investigate the influence of disk surface temperature on friction performance and surface state of friction pair during the continuous braking of friction pair between copper based powder metallurgy brake pad and steel disk,a friction pair paired with copper-based powder metallurgy and steel discs was used,and a 30 s continuous braking test was carried out in a 1∶1 high-speed train brake test rig under different speed and pressure conditions.The change of the disc surface temperature and the friction and wear performance of the brake pads was tested during the braking process,and the surface state of the brake pads was observed.The test results show that during continuous braking,when the maximum temperature of the disc surface is lower than 350 ℃,the instantaneous friction coefficient increases,the brake pad surface is a loose third body,and there are spalling pits on the surface.When the maximum temperature of the disc surface is higher than 350 ℃,the instantaneous friction coefficient is reduced,the fluidity of the third body is enhanced,and a compact third body is formed on the surface,and cracks appear.When the maximum temperature of the disc surface exceeds 600 ℃,a tortoise crack appears on the surface of the brake pad,large-area peeling occurs on the friction surface,and the brake pad is damaged.