AZ80镁合金筒形件微弧氧化膜缺陷分析及改进

Analysis on defects of micro-arc oxidation film on cylindrical AZ80 magnesium alloy part and countermeasures

针对AZ80镁合金筒形件微弧氧化膜表面存在沿挤压方向分布的灰黑色线条问题,借助X射线衍射仪、扫描电镜、能谱仪和金相显微镜分析了镁合金基材的组织结构和元素组成,认为该缺陷的形成与基材中β-Mg;Al;物相偏析有关。降低基材挤压温度和延长微弧氧化时间后缺陷消除。

Aiming at the problem of gray-black strips distributed on micro-arc oxide film surface along the extrusion direction of a cylindrical AZ80 magnesium alloy part, the microstructure and elemental composition of the part were analyzed by X-ray diffraction, scanning electron microscopy, energy-dispersive spectrometry, and metallurgical microscopy. It was found that the formation of these defects was arisen from the segregation of β-Mg;Al;phase in the substrate. The defects could be eliminated by lowering the extrusion temperature of substrate and prolonging the micro-arc oxidation time.