不同转速下弹性环滚动载流摩擦性能和损伤分析

采用内滚道、外滚道和弹性环组成滚动载流摩擦副，通过载流摩擦试验研究了其在不同转速下的载流摩擦学性能和材料损伤。结果表明：随着转速从240 r/min增加到600 r/min,摩擦副稳态运行期间的摩擦力升高，接触电阻下降；摩擦前期材料损伤形式主要以接触表面金属塑性变形为主，摩擦平稳期以材料剥落为主；在相同的初始接触条件下，高转速促进表面疲劳和材料磨损，试验后弹性环磨痕宽度明显变宽，磨损量逐渐增大，表面氧化程度下降，O和Cu原子个数比降低；磨痕宽度增幅相近的条件下，同等转速下的摩擦力增幅小于变速条件下的摩擦力增幅；转速增加引起的摩擦力增大与高转速下弹性环滑滚增加也有关系。

Current-carrying Tribological Behaviors and Damages of Elastic Ring at Different Rolling Speeds

The rolling current-carrying friction pair is composed of inner raceway,outer raceway and elastic ring.The current-carrying friction tests were carried out to study the tribological properties and material damage of the friction pair under different rotational speeds.It is found that as the rotation speed increased from 240 r/min to 600 r/min,the total friction force during the steady-state period increases and the contact resistance decreases.At the early rolling stage,the material damage style is mainly plastic deformation of the contact surface,then turns to be the material peeling at the stable rolling period.Under the same initial contact conditions,high rotation speed promotes surface fatigue and material wear.After the experiments,the width of the wear scar significantly widens and the wear amount increases,the ratio of O and Cu atoms decreases,indicating the deceasing of the oxidation degree of the wear surface.Under the condition of similar increase in wear scar width,the increase in friction force at the same speed is smaller than that under variable speed conditions.Based on the motion video of the elastic ring,it is shown that the sliding/rolling of the elastic ring at high rotational speed has an impact on the increase of friction.