外加载荷对碳纳米管-银-石墨复合材料电磨损性能的影响

Effect of pressure on electrical wear of CNTs-Ag-G composites

研究了压力变化对碳纳米管银石墨复合材料纯机械磨损和电磨损性能的影响。结果表明:在纯机械磨损条件下,随着压力的增加,复合材料的磨损体积线性增加;在电磨损条件下,复合材料的磨损体积与压力成U型变化;当压力过小时,由于电气磨损量大以及电刷跳动产生的火花磨损,导致复合材料的电磨损体积较大;当压力过大时,破坏了电刷和换向器之间形成的润滑膜,产生严重的犁削和粘着磨损,使复合材料的电磨损体积急剧增大;复合材料的电磨损体积与电刷的极性有关,正刷的磨损体积大于负刷的磨损体积;随着压力的增大,复合材料的摩擦系数也随之增大,且在相同条件下,电磨损时的摩擦系数大于纯机械磨损时的摩擦系数;碳纳米管的加入可以提高复合材料的抗电磨损性能。

The effect of pressure various on the mechanical and electrical wear properties of CNTs-Ag-G composites at 10 A/cm^2 were studied, The results show that the wear volume loss of composites increases with the increase of pressure under mechanical wear, but the wear volume loss of composites varies with the change of pressure by U shape under electrical wear. When the pressure become smaller, the electrical wear volume loss of composites become larger because of the additional electrical and spark wear. When the pressure is bigger, the electrical wear volume loss also become larger due to the discontinuous lubricating film, adhesion and ploughing. The wear volume loss of positive brush is more than that of negative brush. The friction coefficient of composites increases with the increase of pressure, and the friction coefficient of composites under electrical wear is greater than that under mechanical wear. Addition of CNTs-Ag-G can improve the electrical friction and wear properties of composites.