微观结构对AZ91镁合金上LDH涂层原位形成的影响。

Impact of Microstructure on the In Situ Formation of LDH Coatings on AZ91 Magnesium Alloy.

作者信息

Wang Nan, Song Yulai, Yu Anda, Tian Yong, Chen Hao

机构信息

Key Laboratory of Automobile Materials, Ministry of Education, College of Materials Science and Engineering, Jilin University, Changchun 130022, China.

出版信息

Materials (Basel). 2025 Mar 6;18(5):1178. doi: 10.3390/ma18051178.

DOI:10.3390/ma18051178

PMID:40077403

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11901571/

Abstract

Layered Double Hydroxide (LDH) coatings were synthesized on as-cast, T4 (solution treatment), and T6 (aging treatment) AZ91 magnesium alloys using a hydrothermal method. XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscope) analyses showed that the large β-phases in as-cast AZ91 initially promoted LDH growth via galvanic corrosion, but later compromised coating integrity. In contrast, T6 and T4 alloys, with refined microstructures, formed uniform and compact LDH coatings. Corrosion resistance was enhanced in T6 and T4 alloys, as evidenced by higher impedance from EIS (Electrochemical Impedance Spectroscopy), and HER (Hydrogen Evolution Reaction) tests, due to the formation of dense LDH layers.

摘要

采用水热法在铸态、T4（固溶处理）和T6（时效处理）的AZ91镁合金上合成了层状双氢氧化物（LDH）涂层。X射线衍射（XRD）和扫描电子显微镜（SEM）分析表明，铸态AZ91中的大β相最初通过电偶腐蚀促进了LDH的生长，但后来损害了涂层的完整性。相比之下，具有细化微观结构的T6和T4合金形成了均匀致密的LDH涂层。T6和T4合金的耐腐蚀性增强，这通过电化学阻抗谱（EIS）和析氢反应（HER）测试中更高的阻抗得到证明，这是由于形成了致密的LDH层。