石墨类型对铜基粉末冶金摩擦材料摩擦磨损性能的影响

Effect of graphite lubrication component type on the microstructure formation and properties of high-speed braking Cu-based friction materials

采用粉末冶金方法制备了分别以鳞片石墨、球形石墨、焦炭、人造石墨和隐晶石墨为润滑组元的铜基摩擦材料,使用MM3000摩擦磨损试验机测试了摩擦磨损和制动性能。结果表明:在3 000~7 000 r/min的转速下,含人造石墨铜基摩擦材料的平均摩擦因数最高,但磨损量大;含焦炭铜基摩擦材料的摩擦因数次之,但磨损量最小,优于含鳞片石墨铜基摩擦材料。在7 000 r/min转速制动条件下,含人造石墨铜基摩擦材料的瞬时摩擦因数最高,制动时间最短,但摩擦材料表面温升最大;含焦炭铜基摩擦材料的瞬时摩擦因数和制动时间次之,但摩擦材料表面温升最小,且整体性能优于常用的含鳞片石墨铜基摩擦材料。因此,相比而言,以焦炭作为润滑组元的铜基摩擦材料具有最佳的摩擦磨损和制动性能。

Cu-based friction materials with different lubrication component such as the flake graphite,spherical graphite,coke,artificial graphite,and cryptocrystalline graphite,were prepared by powder metallurgy technology.The tribological and brake performance of Cu-based friction materials with different lubrication component were tested by the MM3000 friction and wear tester.The results show that the average friction coefficient of the Cubased friction material with artificial graphite as lubrication component is the highest(>0.40),but the wear loss is the largest of all at the speed of 3000~7000 r/min.The friction coefficient of the Cu-based friction material with coke is the second(>0.375),and the wear loss is the smallest of all.The friction coefficient and wear loss of the Cu-based friction material with coke is good than the Cu-based friction material with commonly used flake graph-ite.Under the braking condition of 7000 r/min,the instantaneous friction coefficient of Cu-based friction material with artificial graphite is the highest,and the braking time is short.However,the surface temperature rise of the Cu based friction material with artificial graphite is the largest.The instantaneous friction coefficient and braking time of the Cu-based friction material with coke is second,but the surface temperature rise of friction material is the smallest.The overall performance of the Cu-based friction material with coke is better than the friction material with flake graphite.Therefore,Cu-based friction materials with coke as lubrication component have better tribolog-ical and braking properties,relatively.