刹车速度对铜基粉末冶金摩擦材料性能的影响

以粉末冶金法制备铜基粉末冶金摩擦材料, 采用洛氏硬度计和夏比冲击试验机对摩擦材料的力学性能进行表征, 利用MM-3000型摩擦磨损性能试验台研究了刹车速度对材料摩擦磨损性能的影响, 并借助电子扫描显微镜(scanning electron microscope, SEM)观察了摩擦材料的微观形貌。研究表明:铜基粉末冶金摩擦材料的摩擦磨损性能与刹车速度密切相关, 随着刹车速度的增大, 摩擦吸收功率近似线性增长, 而摩擦系数呈先增大后减小的趋势; 在高速刹车条件下, 铜基体自身发生软化会破坏摩擦材料表面形成的氧化膜, 降低了分子键的抗剪切强度, 从而增大了磨损量。

Effects of braking velocity on friction properties of Cu-based powder metallurgy friction material

Cu-based powder metallurgy friction material was prepared by powder metallurgy technology. Mechanical properties were studied by hardness tester and Charpy impact test machine, the effects of braking velocity on friction and wear properties were investigated by MM3000 friction and wear tester, and the micromorphology of friction material was characterized by scanning electron microscope (SEM). The results show that, the friction and wear properties of Cu-based powder metallurgy friction material are related to braking velocity, the friction absorption powers present almost linear growth, and the friction coefficients increase firstly and then decrease with the increase of braking velocity. Softening of copper matrix can destroy the oxide film on friction material surface, reducing the shear strength of molecular bond and increasing wear loss.