Friction Performance of Cu-based Powder Metallurgy Dry Friction Pairs in Running-in Process

The running-in process of dry clutch friction pairs is crucial to the friction performance. By using the dry clutch friction pairs, a copper-based powder metallurgy friction plate on a 65Mn steel plate, the loading condition table was established according to the working condition in practice. Universal Material Tester (UMT-5) was used to conduct using a pin-on-disc configuration. The average friction coefficient H during sampling time and the coefficient of friction vibration D were introduced to recognize the running-in condition. And then, the effects of speed, load and temperature on the running-in process and the influence of the running-in process on the friction performance were analyzed. The surface morphology was observed by white light interferometer and surface roughness was obtained. The average friction coefficient H lower than 0.02 and the coefficient of friction vibration D lower than 0.16 were indication of the end of running-in process. Loading conditions had a significant impact on the running-in efficiency. Compared with speed and load, the temperature had a greater influence on the wear of the friction pair during the running-in process. After running-in process, the friction coefficient decreased by 35%~45% and was stable. In addition, the wear decreased by 30%~40%. In the running-in time, the surface roughness decreased rapidly in the initial stage and then tended to be stable.