Plasma Electrolytic Oxidation (PEO) is a surface treatment, similar to anodizing, that produces thick oxide films on the surface of metals. In the present work, PEO coatings were obtained on zinc-aluminized (ZA) carbon steel using a solution containing sodium silicate and potassium hydroxide as electrolyte, and working with high current densities and short treatment times in Direct Current (DC) mode. The thickness of the coating, as well as the surface morphology, were strongly influenced by the process parameters, with different dissolution grades of the ZA layer depending on the current density and treatment time. A compromise between thickness and porosity of the coating was found with low current density/long treatment time or high current density/short treatment time. The PEO layer was mainly composed of aluminum oxides and silicon compounds. The corrosion resistance increased remarkably in the samples with the PEO coating. These PEO coated samples are suitable for sealing treatments that further increase their corrosion properties or will be also an ideal substrate for commercial painting, assuring improved mechanical adhesion and protection even in the presence of damages.

中文翻译：

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PEO涂层镀锌铝（ZA）钢的组织和腐蚀性能

等离子体电解氧化（PEO）是一种类似于阳极氧化的表面处理，可在金属表面产生厚的氧化膜。在目前的工作中，使用包含硅酸钠和氢氧化钾的溶液作为电解质，在锌铝化（ZA）碳钢上获得PEO涂层，并在高电流密度下以直流（DC）模式工作很短的时间。涂层的厚度以及表面形态会受到工艺参数的强烈影响，ZA层的不同溶解度取决于电流密度和处理时间。在低电流密度/长处理时间或高电流密度/短处理时间下，发现涂层厚度和孔隙率之间存在折衷。PEO层主要由氧化铝和硅化合物组成。带有PEO涂层的样品的耐腐蚀性显着提高。这些PEO涂层的样品适用于进一步提高其腐蚀性能的密封处理，也将是用于工业喷漆的理想基材，即使在存在损坏的情况下也可确保改善的机械粘合性和保护。