7A52铝合金微动磨损行为研究

Fretting Wear Behavior of 7A52 Aluminum Alloy

利用微动磨损试验机研究7A52铝合金的微动磨损行为,分析不同载荷、振幅、循环次数等参数对摩擦因数和磨损体积的影响,观察分析不同振幅下的磨痕形貌,检测磨痕微区及磨粒的成分组成,探讨其磨损机制。结果表明:7A52铝合金的摩擦因数在不同振幅下的变化趋势不同,微动振幅较大时,实验初期摩擦因数迅速升高,而振幅较小时摩擦因数没有这种现象;磨损体积随着循环次数、振幅、载荷的增加而增加;振幅较小时微动磨损机制主要为磨粒磨损,振幅较大时磨损机制则以黏着磨损和磨粒磨损为主,随着振幅的进一步增加逐渐出现接触疲劳磨损。

The fretting wear behavior of 7A52 aluminum alloy was investigated with a micro-fretting wear tester. The effects of normal load, vibration amplitude and frequency on friction coefficient and wear volume were analyzed. Worn surface under different vibration amplitude was observed. Chemical composition of the worn scar and worn particles was analyzed by EDAX. Wear mechanisms of the fretting test was investigated. The results showed that larger vibration amplitude lead to abrupt rise of the friction coefficient in the initial stage of the fretting, while with lower vibration amplitude, no such phenomenon was observed. Wear volume increased with increasing vibration cycles, larger vibra- tion amplitude and normal load. Under lower vibration amplitude, only abrasive wear was found, while under higher vibration amplitude adhesion occurred in addition to abrasion. With further increased vibration amplitude, contact fatigue wear was also observed.