Developing levodopa-modified sol-gel coating with enhanced anticorrosion performance on Mg alloy AZ31. Issue 3 (7th April 2023)

• Record Type: Journal Article
• Authors: Li, Jiao; Li, Tianshu; Yuwono, Jodie A.; Meng, Guozhe; Feng, Zhiyuan
• Is Part Of: Anti-corrosion methods and materials. Volume 70:Issue 3(2023)
• Page Start: 129
• Page End: 138
• Publication Date: 2023-04-07
• Subjects: Corrosion -- Coating -- sol-gel -- Mg alloy -- Levodopa; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1108/ACMM-03-2023-2765
• Languages: English
• ISSNs: 0003-5599

Abstract

Abstract : Purpose: This study aims to develop a sol-gel-based coating to provide a long-lasting corrosion protection on AZ31 Mg alloy. Silane-based sol-gel coatings have been successfully applied to Mg alloys for corrosion protection. However, the micro or nano defects formed during condensation and solidification will cause the coating failure during a long-lasting immersion in a saline solution. More durable corrosion-protective sol-gel coatings are needed. Design/methodology/approach: A sol-gel-based coating was modified on AZ31 Mg alloy by levodopa (DOPA). The long-lasting corrosion protection mechanism was studied by multiple electrochemical testing methods and surface characterization techniques. Findings: Long-term testing by electrochemical impedance spectroscopy in aqueous 0.1 M NaCl indicated that the modified DOPA@sol-gel coating exhibited significant corrosion protection performance (>14 days). In comparison, the DOPA-free sol-gel coating failed only after three days of testing. The improved corrosion protection is attributed to the self-polymerized DOPA filling to the micro or nano defects in the glassy cross-linked networks of the sol-gel coating, which greatly improves the compactness of the coating. Originality/value: The method of this study is simple and easy to process, the raw materials are green and the protective effect is excellent, which is of significance for the study of magnesium alloy corrosion protection.