高铝铜合金粗粉超音速等离子喷涂层的边界润滑摩擦特性

Boundary lubrication tribological property of high-aluminium copper alloy coarse powders coating made by supersonic plasma spraying

采用超音速等离子喷涂技术在45#钢基体上制备高铝铜合金粗粉涂层,对涂层进行边界润滑摩擦实验,分析涂层的摩擦磨损特征及表面元素的质量损失。结果发现:涂层的摩擦因数随外加载荷的增加呈逐渐下降趋势;尽管磨损量随载荷的增大逐渐增加,但磨损率呈下降趋势,表明随外加载荷的增加涂层耐磨性能逐渐增强。涂层在中低载荷下以磨粒磨损为主,当载荷达到高载荷540 N时,涂层由磨粒磨损向疲劳磨损转变,并在犁沟边缘发生疲劳磨损的同时表现出轻度的粘着磨损。边界润滑条件下,涂层元素的质量磨损主要表现为Cu元素的损失,磨粒磨损留下的犁沟为O元素进入摩擦界面提供通道,使涂层表面形成微氧化膜。

The high-aluminium copper alloy coarse powders coating was fabricated on 45# steel substrate by supersonic plasma spraying.The friction experiment was carried out in the boundary lubrication conditions,and then,the frictional and wear characteristics and the surface elements mass loss of the coating were analyzed.The results show that the friction coefficient of the coating has a gradual decline trend with the increase of the loads,although the wear loss gradually increases with the increase of the loads,the wear rate shows the downward trend,indicating that the wear-resisting performance of the coating is gradually strengthened with the increase of loads.The main wear mechanism of the coating is abrasive wear in the conditions of the low and middle loads,and then the mechanism transforms to fatigue wear when the load reaches 540 N.At the same time,fatigue wear of the coating not only happens in furrows edge, but also mild adhesion appears.In the boundary lubrication conditions,the wear mass loss of the coating elements mainly shows the loss of Cu element,and the furrows left by abrasive wear provide the channels for O element into friction interface,bringing about the tiny oxidation film on surface of the coating.