AZ31镁合金表面聚多巴胺膜的一步制备及腐蚀行为研究

One-step Preparation and Corrosion Behavior of Polydopamine Coatings on Mg-alloy AZ31

利用简单的一步浸渍沉积,直接在AZ31镁合金表面制备了聚多巴胺膜层。用扫描电镜(SEM)和原子力显微镜(AFM)观察了膜层的形貌,用X射线光电子谱(XPS)对膜层成分进行了分析,用动电位极化曲线对膜层的腐蚀行为进行了研究,并通过胶带实验对膜层与基体的结合性能进行考察。结果表明,通过调整实验参数,经一步浸渍法能在镁合金表面制备完整的聚多巴胺膜层,膜层与AZ31镁合金基体结合良好,在SBF溶液中能提高镁合金的耐蚀性能。

Polydopamine coatings were applied on Mg-alloy AZ31 through immersion the alloy into appropriate solutions of polydopamine for a period of time. The surface morphology, chemical composition and adhesive strength to the substrate of coatings were characterized by SEM and AFM, XPS and tensile test respectively. Then their corrosion performance in a simulated body fluid（SBF） solution was assessed by means of potentiodynamic polarization curves. Results demonstrate that the coating showed not only compact structure, but also high bonding strength; the prepared polydopamine coatings can effectively protect the Mg-alloy from corrosion in the simulated body fluid. The approach presented here would be a simple and effective alternative for Mg-alloy surface modification.