摩擦条件对钢质摩擦材料第三体及磨损的影响

Effects of friction condition on the third body and wear properties of steel friction material

摩擦条件对摩擦材料表面第三体的连续性产生重要影响,进而影响材料的摩擦磨损性能.选用两种轨道车辆用低合金制动盘材料与铜基粉末冶金材料为配对摩擦副,在不同速度、压力条件下进行摩擦试验,观察第三体的形成过程中,表面形貌的变化规律及磨损机理.结果表明：在特定的摩擦条件下,第三体的显微硬度可达800~900HV,远高于基体材料的硬度;连续、致密的第三体,使材料具有最低的磨损率;当摩擦转速和压力过低时,磨粒磨损为主要磨损形式,当摩擦转速和压力过高时,黏着磨损将成为主导;在第三体的形成破坏过程中,摩擦速度、压力过低或过高均可能使第三体的破坏速度大于形成速度,使材料的磨损率增大.

Friction condition is an important factor of continuity of third body which has a significant impact on the friction performance of materials. In this paper, two kinds of low alloy steel for railway brake disc and Cu- matrix powder metallurgy material were chosen as friction pairs. Friction tests were conducted under different sliding speeds and pressures. Micro appearance d third body was observed during its formation process and the wear mechanism was explained. Results showed that under certain friction condition, microhardness of the third body wached range between 800 and 900 HV, which was much higher than the fiction materials. With tight and continuous third body, wear rate of the specimens were the lowest. The main mechanisros were abrasive wear when sliding speed and pressure was too low, and adhesive wear was obvious when the parameters were too high. During the friction process, wear rate of friction materials increased when destruction rate of third body was higher than its formation rate.