三种微弧氧化镁合金高温油润滑条件下的摩擦学性能

Tribological Behavior of Three Microarc Oxidation Coatings on Magnesium Alloy with Oil Lubrication at Elevated Temperature

选择三种常用的基础电解液:硅酸盐、磷酸盐、铝酸盐制备了镁合金微弧氧化(MAO)膜,研究了这三种氧化膜在高温油润滑条件下的摩擦学性能.利用SRV摩擦实验机,使样品在20 N的外加载荷,振幅3 mm,频率5 Hz的条件下,与直径10 mm的CCr15钢球分别在室温、80℃、100℃和120℃四个温度,油润滑条件下对磨,结果表明硅酸盐膜层具有最好的摩擦性能,另外两种膜层不仅没有起到抗磨损的作用,反而使磨损加剧.

The ceramic coating on AM60B magnesium alloy was prepared in phosphate, aluminate, and silicate electrolyte by MAO （microarc oxidation） method seperately. The tribological performance of the three different MAO coatings and magnesium alloy under oil-lubricated conditions at 20 N load and oil temperature （80 ℃ - 120 ℃） during engine operation was investigated. Results shown that the MAO coating formed in silicate electrolyte has the best tribological performance among the samples, while the phosphate coating has the poorest performance. The different tribological performance can be attributed to the hardness and micro-pores structure feature of the MAO coatings, under high load, the MAO coatings has low hardness could promote the wear development.