扭动微动的模拟及其试验研究

Experimental Investigation and Simulation of Tortional Fretting Mode

在CETRUMT-2型多功能摩擦磨损试验机上配置高精度低速往复转动台，构成新型试验装置并成功实现了球／平面接触条件下的扭动微动；在低速往复转动台上进行了GCr15钢球（直径10mm）与IZSO钢在扭动角位移幅值为3°～20°和法向载荷10N时的扭动微动试验，并在分析其摩擦动力学行为的基础上对LZ50钢的扭动微动损伤特征进行探讨．结果表明：角位移幅值和循环次数对扭动微动行为影响很大；可以通过摩擦力矩-角位移（T-θ）曲线表征扭动微动行为；随着循环次数变化，T-O曲线呈3种基本类型，即平行四边形状、椭圆状和直线状．扭动微动损伤在低角位移幅值时较轻微，随着角位移幅值增加，出现塑性流动、氧化磨损和剥层。

With configuration of ball-on-flat contact, torsional fretting mode was realized successfully on a newly developed fretting test rig which collocated a low-speed reciprocating motor with a high-precision on CETR UMT-2 mutifunctional friction and wear tester. The torsional fretting tests of 1,750 steel flat against GCrl5 steel ball with a diameter of 10 mm were carried out under various angular displacement amplitudes from 3° to 20° and imposed normal load of 10 N. Based on the analysis of the frictional kinetics of torsional fretting, the damage characteristics of IZ50 steel were also discussed in detail. The behavior of torsional fretting was strongly depended upon the angular displacement amplitudes and the number of cycles, which was characterized by the curves of friction torque/angular displacement （T-O）. Varied with the number of cycles, there were three basic types T-O curves during the process of torsional fretting, i.e. parallelogram, elliptical and linear T-O curves. The damage of torsional fretting at lower angular displacement amplitude was very slight. With increasing angular displacement amplitude, plastic flow, oxidative wear and delamination were observed.