Lashkarara S, Fazlali A, Ghaseminezhad K, Fleck C, Salavati M
Fachgebiet Werkstofftechnik/Chair of Materials Science & Engineering, Institute of Materials Science and Technology, Faculty III Process Sciences, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin, Germany.
Chemical Engineering Department, Technical and Engineering Department, Arak University, Sardasht Square, Arak, 38156879, Iran.
Sci Rep. 2024 Mar 28;14(1):7380. doi: 10.1038/s41598-024-58008-8.
Plasma electrolytic oxidation (PEO), applied to light metals such as titanium, aluminum, and magnesium, creates a two-layer coating and has become increasingly important in metal coatings. However, due to the high voltage and temperature of the process, no online instrument could monitor the underlying mechanism. This paper presents a new image proving that the surface of PEO-coated Mg3ZnCa boiled during the process and argues that three hypotheses are involved in the PEO mechanism based on boiling caused by tolerating high voltage during the PEO process, which could explain the current‒voltage diagram of the process. Finally, nanoindentation was used to measure the elastic module and hardness of the PEO layers. The nanoindentation test results revealed the similarity of the elastic module of the outer porous layer and the primary alloy, with values of 40.25 GPa and 41.47 GPa, respectively, confirming that the outer porous layer corresponds to the cold plasma-gas phase formed during the PEO process.
等离子体电解氧化（PEO）应用于钛、铝和镁等轻金属时，会形成两层涂层，在金属涂层领域变得越来越重要。然而，由于该工艺的高电压和高温，没有在线仪器能够监测其潜在机制。本文展示了一幅新图像，证明在该过程中PEO涂层的Mg3ZnCa表面会沸腾，并基于PEO过程中耐受高电压引起的沸腾现象，提出了PEO机制涉及的三个假设，这些假设可以解释该过程的电流-电压图。最后，使用纳米压痕法测量了PEO层的弹性模量和硬度。纳米压痕测试结果显示，外层多孔层和原始合金的弹性模量相似，分别为40.25 GPa和41.47 GPa，证实外层多孔层对应于PEO过程中形成的冷等离子体-气相。
