微弧氧化涂层的微动磨损行为研究

Behaviors of Fretting Wear of Microarc Oxidation Coating

在弱碱性电解质液中,采用电弧放电于铝合金表面原位生长制备出厚度约10μm的A l2O3陶瓷微弧氧化涂层,研究微弧氧化涂层及铝合金基体在干态不同位移幅值下的微动磨损行为及其动力学特性,采用激光共焦扫描显微镜和扫描电子显微镜观察磨痕微观形貌.结果表明:涂层改变了铝合金的微动运行区域,使得混合区和滑移区向小位移方向移动;涂层表面比较粗糙,与铝合金基体相比,在微动初期的摩擦系数较高,但在稳定阶段的摩擦系数有所降低;微弧氧化涂层可以显著降低铝合金的磨损,在部分滑移区损伤轻微,随着位移幅增加磨损加剧;在混合区和滑移区,涂层的损伤主要表现为剥层.

LD11 aluminium alloy surface was treated with microarc oxidation （MAO）. Fretting wear tests of the microarc oxidation coating and its substrate were carried out under different displacement amplitudes. Dynamic analyses in combination with microscopic examinations through Laser Confocual Scanning Microscope and Scanning Electric Microscope were performed. Results show that fretting regimes of such MAO coating were changed, i.e. the mixed and slip regime shifted to the smaller displacement. Compared with the substrate material, friction coefficient was higher in initial stage due to its coarse surface, and was lower in steady stage. Wear of material reduced for the MAO coating specimens. In the fretting regime of partial slip, damage was very slight, but the wear increased with the increase of the displacement amplitude. In mixed and slip regime, the damage mechanism of the MAO coating was mainly delamination.