Novel green and ecofriendly route for fabricating a robust corrosion protection coating on AZ91D magnesium alloy

• Published in: Electrochemistry communications 2024-03, Vol.160, p.107667, Article 107667
• Main Authors: Jian, Shun-Yi, Liu, Yu-Cheng, Chang, Chin-Jou
• Format: Article
• Language: English
• Subjects: AZ91D magnesium alloy; Electrochemical impedance spectroscopy (EIS); Green and ecofriendly; Microstructure; Salt spray test
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2024.107667

[Display omitted] •A novel green and ecofriendly route with low energy consumption, fast and simple.•Electroconversion-coated AZ91D plates provide robust corrosion protective ability.•A compact and single-layered film with average thickness of 1750 nm.•The coating is more anticorrosive than that yielded through anodizing treatment.•The corrosion area of the coating less than 5 % after 168 h SST. Mg is the lightest structural metal on earth; hence, applications of its alloys have attracted attention from researchers. However, these alloys have poor corrosion resistance, which impedes their use in practice. Many researchers have investigated protective coatings for Mg alloys, but current methods consume much energy, use hazardous substances, or are complex (such as anodizing and micro-arc oxidation). This paper proposes a novel method of creating a durable and protective coating on Mg alloy substrates. The AZ91D Mg alloy was selected for investigation, and a Mn-V-P conversion coating treatment in which voltage of only 5 V was applied for 1 min to enhance the alloy’s corrosion resistance. A compact, single-layer film with uniform thickness was created; the average thickness was 1750 nm. The corrosion resistance of alloys treated with the method and through anodizing treatment was compared. For the novel coating, the corroded area fraction after a 168-h salt spray test was less than 5 %, superior to that for the coating produced through anodizing treatment. The feasibility and potential applications of the novel process are discussed.