LDH conversion films for active protection of AZ31 Mg alloy
LDH conversion films for active protection of AZ31 Mg alloy
复制标题
DOI：
10.1016/j.jma.2022.09.014
复制
发表时间：
2022-10
影响因子：
17.6
通讯作者：
B. Pillado;B. Mingo;R. del Olmo;E. Matykina;A. Kooijman;Y. Gonzalez−Garcia;R. Arrabal;M. Mohedano
中科院分区：
文献类型：
--
作者：
B. Pillado;B. Mingo;R. del Olmo;E. Matykina;A. Kooijman;Y. Gonzalez−Garcia;R. Arrabal;M. Mohedano
在AZ 31镁合金表面成功制备了锌铝（Zn-Al）和锂铝（Li-Al）-层状双氢氧化物（LDH）复合缓蚀剂涂层。Zn-Al LDH W和Li-Al LDH Li显示出最高的耐腐蚀性，并被选择用于进一步评估。SEM横截面检查显示了一个双层结构，由松散薄片的外部和致密的内层组成。XRD、FTIR和XPS分析证实了抑制剂的掺入。用含有缓蚀剂的溶液进行后处理，导致LDH涂层最外层的选择性溶解，降低了表面粗糙度、亲水性和涂层的附着力。通过SVET评估确认了Zn-Al LDH W涂层的活性腐蚀性能。所提出的活性腐蚀机制涉及侵蚀性Cl−离子的离子交换、氢氧化物的沉积和富W腐蚀抑制剂的竞争性吸附。
Zinc aluminium (Zn-Al) and lithium aluminium (Li-Al) – layered double hydroxides (LDH) coatings with incorporated inhibitors (Li−, Mo− and W−based) were successfully synthesized on AZ31 Mg alloy. Zn−Al LDH W and Li−Al LDH Li showed the highest corrosion resistance and were selected for further evaluation. SEM cross−section examination revealed a bi−layer structure composed of an outer part with loose flakes and a denser inner layer. XRD, FTIR, and XPS analysis confirmed the incorporation of the inhibitors. Post−treatments with corrosion inhibitors containing solutions resulted in the selective dissolution of the most external layer of the LDH coating, reducing the surface roughness, hydrophilicity and paint adhesion of the layers. Active corrosion properties were confirmed by SVET evaluation for the Zn−Al LDH W coating. The proposed active corrosion mechanism involves the ion−exchange of aggressive Cl−ions, deposition of hydroxides and competitive adsorption of W−rich corrosion inhibitors.