Wang Yifei, Liu Chunming, Li Hongzhan, Zhang Zhen
School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China.
Northwest Institute for Non-Ferrous Metal Research, Xi'an 710016, China.
Materials (Basel). 2025 Apr 30;18(9):2072. doi: 10.3390/ma18092072.
This study investigates the enhancement of corrosion resistance in magnesium-lithium alloys through plasma electrolytic oxidation (PEO) coatings incorporating ZnF via in situ synthesis. By adjusting Zn⁺ concentrations (4-16 g/L) in a zirconium salt-based electrolyte, ceramic coatings with tailored ZnF content, thickness, and porosity were fabricated. The optimal Zn⁺ concentration of 12 g/L yielded a ZnF-rich coating with isolated pores and enhanced densification (inner layer resistance R = 3.01 × 10 Ω⋅cm), achieving a corrosion current density (i) of 4.42 × 10 A/cm and polarization resistance () of 8.5 × 10 Ω⋅cm, representing a 354-fold improvement over untreated LA103Z. Higher Zn⁺ concentrations (16 g/L) induced interconnected pores and ZnO formation, degrading corrosion resistance. Long-term immersion (168 h in 3.5 wt% NaCl) confirmed the durability of Zn coatings (mass loss: 0.6 mg), while Zn and Zn coatings exhibited severe localized corrosion. The study demonstrates that balancing Zn⁺ concentration optimizes ZnF passivation and pore isolation, offering a scalable strategy for Mg-Li alloy protection in corrosive environments.
本研究通过原位合成含ZnF的等离子体电解氧化（PEO）涂层来研究镁锂合金耐腐蚀性的增强。通过调整锆盐基电解液中的Zn⁺浓度（4 - 16 g/L），制备了具有定制ZnF含量、厚度和孔隙率的陶瓷涂层。12 g/L的最佳Zn⁺浓度产生了具有孤立孔隙和增强致密化的富含ZnF的涂层（内层电阻R = 3.01×10 Ω⋅cm），实现了4.42×10 A/cm的腐蚀电流密度（i）和8.5×10 Ω⋅cm的极化电阻（），相较于未处理的LA103Z提高了354倍。较高的Zn⁺浓度（16 g/L）导致相互连通的孔隙和ZnO形成，降低了耐腐蚀性。长期浸泡（在3.5 wt% NaCl中浸泡168小时）证实了含Zn涂层的耐久性（质量损失：0.6 mg），而含Zn和含Zn涂层表现出严重的局部腐蚀。该研究表明，平衡Zn⁺浓度可优化ZnF钝化和孔隙隔离，为在腐蚀性环境中保护镁锂合金提供了一种可扩展的策略。
