制动速度对高性能铜基制动闸片性能的影响

Effect of braking speed on the property of high-performance copper-based brake pads

采用传统的粉末冶金方法制备了高性能铜基制动闸片,并与商用铜基制动闸片作对比,在MM-1000Ⅱ型摩擦磨损试验机上对不同制动速度下的制动性能进行了探究,分析了闸片与制动盘的表面形貌。结果表明,随着制动速度的升高,自制闸片的摩擦系数先下降后上升,而商用闸片的摩擦系数降低后保持不变。摩擦系数的下降与摩擦表面摩擦膜的生成有关。随着制动速度的进一步升高,摩擦膜的破裂使得摩擦系数上升,铜的软化使得摩擦系数下降,由此可知,摩擦系数的变化同时受制于二者的综合作用。在180~350 km/h的速度范围内,自制铜基制动闸片比商用铜基制动闸片具有更高的摩擦系数和耐磨性,并在连续紧急制动过程中,也具有更大的摩擦系数波动。

High-performance copper-based brake pads were prepared by the traditional powder metallurgy method,and the commercial copper-based brake pads were used as a comparison.The braking performance under the different braking speeds was studied on MM-1000Ⅱfriction and wear tester,and the surface morphology of the brake pads and the brake discs were analyzed.The results show that,with the increase of the braking speed,the friction coefficient of the self-made brake pads first decreases and then increases,while the friction coefficient of the commercial brake pads remains unchanged after decreasing.The reduction of friction coefficient is related to the formation of friction film.With the further increase of the braking speed,the rupture of the friction film results in the increase of the friction coefficient,while the softening of copper makes the friction coefficient decrease.The change of friction coefficient is subject to the combined action of the friction film and the copper softening.In the speed range of 180~350 km/h,the self-made copper-based brake pads have the higher friction coefficient and wear resistance than the commercial ones,and show the higher friction coefficient fluctuation in the process of the continuous emergency braking.