Abstract A Ni20Cr coating surface with a micro-nano hierarchical structure was successfully prepared by shrouded plasma spraying method in the present study. By adjusting the spraying parameters to control the heating degree of the powder particles and using a designed shield deposition method, we confirmed that the nanostructures were the products of vapor deposition by vaporization of the material during the spraying. In addition, an interesting phenomenon was found that, without any additional chemical modification, the surface with micro-nano structures underwent a wettability transition from super-hydrophilicity to super-hydrophobicity during the storage in air. The results show that the selective spontaneous adsorption of the nanostructures can effectively reduce the surface free energy. The nanostructures deposited on the top of the surface made the surface form a unique hierarchical structure, which can effectively reduce the contact area of the droplet with the surface. Nanostructures affected the wettability of the coating surface both in the chemical composition and the structural aspects, which demonstrated that they were the key to obtaining super-hydrophobic property on the coating surface.

中文翻译：

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等离子喷涂气相沉积对金属Ni20Cr涂层表面形貌和润湿性的影响

摘要 本研究采用等离子喷涂法成功制备了具有微纳米分级结构的Ni20Cr涂层表面。通过调整喷涂参数来控制粉末颗粒的加热程度，并使用设计的屏蔽沉积方法，我们证实纳米结构是喷涂过程中材料汽化的气相沉积产物。此外，还发现了一个有趣的现象，即在没有任何额外化学修饰的情况下，具有微纳米结构的表面在空气中储存过程中经历了从超亲水性到超疏水性的​​润湿性转变。结果表明，纳米结构的选择性自发吸附能有效降低表面自由能。沉积在表面顶部的纳米结构使表面形成独特的分层结构，可以有效减少液滴与表面的接触面积。纳米结构在化学成分和结构方面影响涂层表面的润湿性，这表明它们是在涂层表面获得超疏水性能的关键。