在新研制的扭动微动磨损实时观测系统上,以法向载荷为100 N和扭动角位移幅值为0.5°~15.0°的参数,对有机玻璃(Polymethylmethacrylate,PMMA)/GCr15摩擦副进行扭动微动磨损试验,同时录制扭动微动过程并同步采集摩擦振动信号。在摩擦动力学行为分析的基础上,结合实时观测和摩擦振动分析,对PMMA的扭动微动磨损行为进行研究。结果表明,随着角位移幅值增加,PMMA扭动微动呈现三个区域(即部分滑移区、混合区和滑移区);在部分滑移状态(θ=0.5°)下,损伤轻微,振动数据与空载时振动数据相似,相对运动主要靠弹性变形协调;在完全滑移状态(θ=15°)下,整个接触区发生严重损伤,大量磨屑被排出接触区,接触区最外侧呈现纺锤状银纹,每循环次数下振动信号的事件发生数先增大后减小,而振动振幅呈现相反的趋势,主要损伤机制为弹塑性变形、剥层和氧化磨损。
The torsional wear tests of polymethylmethacrylate (PMMA)againstGCrl5 is carried out under the angular displacement amplitudes ranging from 0.5° to 15.0° and the normal load at 100 N on a new developed real time observation system of torsional fretting wear, meanwhile, the fretting process is recorded and at the same time the friction vibration is collected. Based on the analysis of the frictional kinetics of torsional fretting, the torsional fretting behavior of PMMA is analyzed by real time observation and friction vibration analysis. The results show that there are three fretting running regimes, i.e. partial slip regime, mixed fretting regime and gross slip regime; when the fretting is running in the state of partial slip (0=-0.5°), the damage is slight and the vibration statistic is similar to load-free condition because the relative motion is accommodated by elastic deformation. In the state of gross slip (0=15,0°), the contact zone is damaged intensely, and a great deal of the wear debris is removed from the contact zone, there are some crazes in shape of spindle at the edge of contact zone. Meanwhile, the events of friction vibration per cycle increases and then decreases with the increase of the number of cycles; on the other hand, the amplitude of friction vibration shows an opposite trend. The main damage mechanisms are elastic-plastic deformation, delarnination and oxidation wear.