B4C含量对高速动车组C/C-SiC制动材料摩擦磨损性能研究

Friction-Wear Properties of B4C Contents to C/C-SiC Brake Materials in High-speed EMU

为提高C/C-SiC摩擦材料的热物理性能和摩擦磨损性能,降低制动过程摩擦面温度,文中采用真空压力浸渍结合化学气相沉积(CVI)和液硅渗透(LSI)制备了B4C改性C/C-SiC摩擦材料(C/C-B4C-SiC),研究了不同B4C含量对C/C-B4C-SiC摩擦磨损性能的影响。结果表明:适量引入B4C可降低制动过程中的摩擦面温度;通过对摩擦磨损性能及磨损机理的分析,表明B4C的引入有利于形成均匀而连续的摩擦膜,使C/C-B4C-SiC制动材料的磨损率在高速制动时降低50%以上。

In order to improve the thermophysical properties of C/C-SiC brake materials,reduce the temperature of friction surface during the braking process,and improve the friction and wear properties of brake materials,vacuum pressure impregnation combined with chemical vapor deposition(CVI)and liquid silicon infiltration(LSI)was used to prepare B4C modified C/C-SiC(C/C-B4C-SiC)brake materials.The effects of different B4C contents on friction and wear properties of the materials were investigated.The results showed that a dense C/C-B4C-SiC composite could reduce the temperature of friction surface during the braking process.The analysis of friction and wear performance and wear mechanism showed that the introduction of B4C was conducive to the formation of a uniform and continuous friction film,resulting in the decrease of the wear rate of C/C-B4C-SiC brake materials by more than 50%at high braking speeds.