2A12 铝合金硬质阳 极氧化及膜层性能研究

目的对混合酸电解液体系中2A12铝合金硬质阳极氧化膜层的制备及性能进行研究。方法采用以硫酸为主的混合酸电解液体系,对2A12铝合金进行硬质阳极氧化,研究混合酸电解液主要成分对2A12硬质阳极氧化膜层性能的作用和影响。结果在硫酸的溶解、有机酸吸附以及添加剂的耦合作用下,混和酸电解液避免了2A12铝合金硬质阳极氧化膜制备过程中存在的烧蚀现象,膜层平均硬度达到400HV0.05以上。WX添加剂能够明显改善2A12铝合金硬氧化膜层的耐蚀性能,经过168 h的中性盐雾试验,仅出现了5%的白霜,但与相同厚度的7A04铝合金硬质阳极氧化膜层相比,耐蚀性较差。结论建议制备有耐蚀性要求的硬质阳极氧化膜层时选用铜含量较低的铝合金材料。

Preparation and Properties of Hard Anodic Oxide Coating on 2A12 Aluminium Alloy

Objective To study the properties of hard anodic oxide coatings on 2A12 aluminum alloy prepared in electrolyte of hybrid acids. Methods Hard anodic oxide coatings were prepared on 2A12 aluminum alloy surface in electrolyte of hybrid acids dominated by sulfuric acid. The effects of hybrid acids were analyzed and characterized. Results The results showed that the phenomenon of ablation could be avoided by the acts of H2SO4, organic acids and additive agents. The surface hardness of coating prepared in electrolyte of hybrid acids was above 400HV0. 05. Additive agent WX could increase the corrosion resistance of hard anodic oxide coatings on 2A12 aluminum alloy surface. Only 5% corrosion area of hard anodic oxide coating on 2A12 aluminum alloy surface was observed after 168 h of neutral salt spray test. Hard anodic oxide coatings on 7A04 aluminum alloy surface showed better corrosion resistance compared with the coatings on 2A12 aluminum alloy surface. Conclusion Aluminum alloys with lower Cu content are suggested for preparing hard anodic oxide coatings with better corrosion resistance.