The Effect of Sintering Temperature on the Microstructures and Properties of Resin-Bonded Copper–Graphite Brush Materials

In this paper, resin-bonded copper–graphite brush materials were prepared by powder metallurgy method with sintering temperatures of 450 °C and 910 °C. The microstructures of both the prepared brush materials and their worn surfaces after current-carrying friction and wear test were characterized. The physical and mechanical properties of the brushes were tested as well. The results indicate that both open pores and MoS₂ are the main factors influencing the abrasion resistance of the brushes. The porosity of the brushes sintered at 450 °C is relatively low, and there is a certain amount of MoS₂ on the worn surface which provides a self-lubricating effect and reduces the wear during the current-carrying friction and wear process. Brushes sintered at 910 °C have higher porosity which leads to more serious cumulative oxidative wear effects. In the meantime, the MoS₂ has decomposed during sintering process, resulting in a relatively poor lubricating effect during friction process.