制动条件对Cu基闸片材料摩擦磨损性能的影响

Effect of Braking Conditions on Tribological Performance of Cu-based Powder Metallurgy Brake Pads

采用粉末冶金工艺制得Cu基摩擦材料。利用MM1000-Ⅱ型摩擦磨损试验机对材料进行性能测试,用扫描电镜观察磨痕并分析磨损机理。分析结果表明：一定制动压力条件下,随着制动速度的增加,摩擦因数和磨损率均呈现先增大后减小的趋势。制动速度为250-300 km/h时,材料的制动性能最好。在不同的制动速度条件下,材料摩擦因数的稳定因数均保持在较大值,材料表面状态较为稳定。一定制动速度条件下,随着制动压力的增加,摩擦因数先增大后减小,磨损率逐步增大并趋于稳定;0.4 MPa时摩擦因数达到最大值0.35,此时材料的制动性能最好。

Cu-based friction materials were fabricated by powder metallurgy. The friction and wear properties were tested on MM1000-Ⅱ tester,and the surface scratches were observed by SEM to analyse the wear mechanism. The results show that when the braking pressure is constant,both friction coeffcient and wear rate increase firstly and then decrease with the increasing of speed. The braking pads achieve the best performance between 250 km / h and 300 km / h. The stable coefficien of the friction coefficient reaches very big value under arbitrary speed,and the material surface condition is stable. If the braking speed remains constant,with the increasing of the braking pressure,the wear rate increases at first and then tends to be steady,while the friction coefficient increases firstly and then decreases. The maximum friction coefficient is 0. 35 when the braking pressure is 0. 4 MPa,and the braking pads achieve the best performance.