Formation of corundum-rich alumina coatings on low-carbon steel by plasma electrolytic oxidation
Formation of corundum-rich alumina coatings on low-carbon steel by plasma electrolytic oxidation
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DOI：
10.1088/1757-899x/1147/1/012007
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
F. Simchen;N. Masoud-Nia;T. Mehner;T. Lampke
中科院分区：
文献类型：
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作者：
F. Simchen;N. Masoud-Nia;T. Mehner;T. Lampke
等离子体电解氧化(PEO)是一种为轻金属及其合金提供陶瓷表面保护的创新方法。然而，对于铁基材料，该工艺需要非常高的电流密度，并导致形成由不太稳定的铁化合物组成的涂层。因此，本研究的目的是在低碳钢上设计一种中等电流密度下的PEO工艺，以形成化学成分由电解液组成主导的陶瓷涂层。所用电解液以铝酸盐为基础，通过系统的电化学钝化实验预先选定。通过电学和光学过程诊断对PEO治疗进行监测。结果是，在C8C钢上，在低于25A/dm2的电流密度下，经过37分钟的处理，可以获得厚度为80微米、刚玉含量约为50%~90%的氧化铝层。但涂层组织结构不均匀，与基体结合力差。根据实验工作的结果，提供了解释方法，并提出了解决这些问题的行动方案。
The plasma electrolytic oxidation (PEO) is an innovative method for providing light metals and their alloys with protective ceramic surfaces. However, for iron-based materials, the process requires very high current densities and results in the formation of coatings which consist of less stable iron compounds. Therefore, it was the aim of this study to design a PEO procedure on low-carbon steel at moderate current densities, which allows for the formation of ceramic coatings whose chemical composition is dominated by the electrolyte constituents. The electrolyte used was based on aluminate and preselected by systematic electrochemical passivation experiments. The PEO treatment was monitored by electrical and optical process diagnostics. As a result of this, it was possible to obtain alumina layers of 80 micrometers in thickness, with a high corundum content of approximately 50 to 90%, after 37 minutes of treatment time, at a current density below 25 A/dm2 on C8C-steel. However, the coating’s microstructure was inhomogeneous and showed poor substrate bonding. Based on the results of the experimental work, explanatory approaches were provided and a course of action is suggested for counteracting these problems.