基于低速往复回转电动机系统和高精度六维力/转矩传感器,通过改变旋转轴的倾斜角α,成功实现了扭转复合微动,该微动属扭动微动和转动微动模式的复合。并对GCr15钢球/50钢平面在倾斜角度为10°和40°及不同扭转角位移幅值下的扭转复合微动进行初步考察,同时结合光学显微镜、扫描电子显微镜、表面轮廓仪等手段分析50钢的扭转复合微动运行行为、磨痕形貌及损伤机理。结果表明,该试验装置能真实模拟扭转复合微动;倾斜角和角位移幅值对扭转复合微动的运行和损伤行为有重要影响;可利用摩擦力—角位移幅值曲线来表征扭转复合微动行为,50钢摩擦力—角位移幅值曲线呈直线型、椭圆型和平行四边形型3种类型;其损伤特征明显不同于单一运行模式控制(扭动微动或转动微动)下的微动行为。此外,不对称的磨斑形貌是扭转复合微动的一个典型特征。
Dual-rotary fretting is successfully realized by changing the tilt angle of rotation axis based on a low-speed reciprocating rotary motor system and a high-precision six-dimensional forces/torques sensor,which combined with the torsional and rotational fretting modes.The dual-rotary fretting tests of 50 steel flat against AISI52100 steel ball are carried out under tilt angle of 10°and 40° and various angular displacement amplitudes from 0.125° to 2°.Kinetic analysis of the fretting running behaviors is performed in combination with microscopic examinations through optical microscopy,scanning electric microscopy,surface profilometer.The results show that the dual-rotary fretting can be truly simulated and is strongly dependent upon the tilt angle and the angular displacement amplitude.Friction force/angular displacement(Ft-θ) curves can be used to characterize the rotational fretting running behavior,the friction force/angular displacement curves of 50 steel exhibit three basic types of linear,elliptical and parallelogram.The running and damage behaviors of dual-rotary fretting are obviously different from simple fretting mode,which is dominated by torsional fretting or rotational fretting.In addition,the asymmetric wear scar is a typical characteristic of dual-rotary fretting.