封孔工艺对2A12航空铝合金微弧氧化膜的影响

Influence of Sealing Process on Micro-Arc Oxidation Film of 2A12 Aviation Aluminum Alloy

封孔工艺对2A12航空铝合金微弧氧化膜层的微孔和裂纹进行了填充,是重要的微弧氧化后处理工艺。本文对比研究了封孔工艺对2A12航空铝合金微弧氧化膜层厚度、硬度、粗糙度和耐蚀性的影响。使用扫描电子显微镜、能谱仪、X射线衍射仪分别对微弧氧化膜层的微观形貌、元素组成、晶相结构进行表征分析,使用涂层测厚仪、维氏显微硬度仪、粗糙度检测仪、酸性盐雾箱分别对封孔工艺处理前后膜层的厚度、硬度、粗糙度、耐蚀性进行测试。对2A12航空铝合金微弧氧化膜层进行硅烷封孔工艺处理,其厚度与硬度无明显变化、粗糙度降低,耐蚀性能显著提升,硅烷3次封孔后的膜层经过酸性盐雾试验192 h无腐蚀痕迹,为后期铝合金微弧氧化在航空领域的应用提供了参考。

The sealing process is an important post-treatment process of micro arc oxidation for 2A12aviation aluminum alloy, which fills the microholes and cracks in the film. The effects of sealing process on the thickness, hardness, roughness and corrosion resistance of 2A12 aviation aluminum alloy micro-arc oxidation film are comparatively studied. Scanning electron microscope, energy dispersive spectroscopy and X-ray diffractometer were used to characterize and analyze the micro-arc oxidation film’s microstructure, elemental composition and crystalline phase structure. Coating thickness tester,vickers microhardness tester, roughness tester and acid salt spray box were used to test the thickness,hardness, roughness and corrosion resistance of the film before and after the sealing process. The micro-arc oxidation film of 2A12 aviation aluminum alloy was treated by silane sealing process. The thickness and hardness have no obvious change, the roughness is reduced, and the corrosion resistance is significantly improved. The film sealed with silane for three times has no corrosion trace after 192 h acid salt spray test, which provides a reference for the application of micro-arc oxidation in aviation field.