TC4合金在不同环境介质中微动磨损行为研究

采用SRV-IV微动磨损试验台,研究TC4钛合金在空气和纯水介质中不同位移幅值下的微动磨损行为及其在模拟海水中的微动腐蚀特性,利用扫描电子显微镜和激光共聚焦显微镜分别对磨痕表面形貌、磨损体积及磨痕轮廓进行表征,分析了钛合金在不同环境介质中的微动磨损机制。结果表明:摩擦系数随位移幅值的增大呈现出先增大后减小的趋势,磨损体积随位移幅值的增大而增大;干摩擦条件下,摩擦系数较高且波动剧烈,磨损体积较小,磨损机制主要为磨粒磨损、粘着磨损并伴有氧化磨损;与干摩擦相比,水介质中的摩擦系数较低,磨损体积显著增大,且模拟海水中的摩擦系数更低更稳定,磨损轮廓更深,说明腐蚀与磨损之间存在"正"交互作用;TC4合金在纯水介质中的微动磨损机制主要为疲劳磨损和磨粒磨损,而在模拟海水中的微动磨损机制主要为磨粒磨损和腐蚀磨损。

Fretting Wear Behavior of TC4 Alloy in Different Environmental Media

The fretting wear behaviors of TC4 titanium alloy under different displacement amplitudes in air, pure water and the artificial seawater of 3.5% NaCl were studied by SRV-IV fretting wear test rig. Scanning electron microscopy and laser scanning confocal microscopy were used to characterize the surface morphology, wear volume and wear profile of the wear scar. Fretting wear mechanism of titanium alloy in different environmental media was analyzed. The results showed that the friction coefficient increase first and then decrease with the increase of the displacement amplitude, while the wear volume increase. Under the dry friction condition, the friction coefficient is higher and unstable, and the wear volume is smaller. The wear mechanism is mainly abrasive wear, adhesive wear and oxidative wear. Compared with dry friction, the friction coefficient in the aqueous water is lower, the wear volume is significantly increased, and the friction coefficient in the artificial seawater is lower and more stable, and the wear profile is deeper, indicating that there is a "positive" interaction between corrosion and wear. The fretting wear mechanism of TC4 alloy in pure water is mainly fatigue wear and abrasive wear; while the fretting wear mechanism in artificial seawater is mainly abrasive wear and corrosion wear.