材料期刊网

在硅酸盐和磷酸盐复合电解液体系下,通过微弧氧化技术在AZ91D镁合金表面制备一层陶瓷涂层.利用XRD、SEM、激光共聚焦显微镜(LSCM)分别对涂层物相、涂层表面、截面和磨痕形貌进行观察分析.采用UMT-3高温摩擦磨损试验机研究涂层在150℃范围内的摩擦磨损性能.结果表明:涂层的平均摩擦系数随温度的变化先逐渐升高,当环境温度高于100℃时涂层平均摩擦系数开始降低.涂层磨损率远远低于镁合金基体磨损率并且涂层磨损率随温度的升高而降低,这说明微弧氧化涂层具有良好的耐磨损性能,尤其在高温条件下耐磨损性能更好.通过分析载荷为2N作用时的磨痕微观形貌可知不同温度条件下涂层的磨损机理都主要为磨粒磨损.

A ceramic coating was formed on AZ91D magnesium alloy by micro arc oxidation technology in aqueous solution containing silicate and phosphate.The phase composition,surface,cross-sectional and wear tracks morphologies of the coating were analyzed by XRD,SEM and Laser Scanning Confocal Microscope (LSCM),respectively.UMT-3 High Temperature Tribometer was used to study the friction and wear behaviors of coating within 150 ℃.The results show that the coatings' mean friction coefficient firstly increases with the temperature increasing.When the ambient temperature exceeds 100 ℃,it begins to reduce.The wear rate of the coating is much lower than that of magnesium alloy substrate,and it declines as temperature goes up.The results indicate that the micro arc oxidation coating has excellent wear resistance particularly at high temperature.Through the analysis of grinding cracks' micro-structure at the load of 2 N,the main wear mechanism of these coatings at different temperatures is all abrasive wear.