(天津大学 材料科学与工程学院， 天津 300072)
摘 要: 利用AlCl3+LiAlH4+MgBr2有机溶剂体系在碳钢基体上电沉积出Al-Mg合金镀层， 并对不同沉积电流密度下Al-Mg镀层的表面形貌、 成分、结构、 厚度、 结合力和耐蚀性进行了研究。 结果表明： 沉积出的铝镁合金镀层表面光滑、 均匀、 致密； 膜层中的镁含量随沉积电流密度的增加而增大， 且以Al-Mg固溶体形式存在， 并按（200）面的结构生长； 随沉积电流密度的增加，铝镁合金镀层的厚度与晶格常数呈线性增大； 在3.5% NaCl溶液中的耐蚀性呈先增大后减小的规律； Al-Mg镀层与碳钢基体的结合力良好， 均大于50 N； Al-Mg镀层的沉积速率、 结合力和耐蚀性均高于相同沉积条件下的纯铝镀层； Al-Mg合金镀层沉积的最佳电流密度为0.75～1.50 A/dm2。
关键字: Al-Mg合金； 电镀； 有机溶剂体系； 组织结构； 耐蚀性
（School of Materials Science and Engineering,
Tianjin University, Tianjin 300072, China）
Abstract: Aluminum-magnesium alloy coatings were electroplated onto carbon steel by using AlCl3+LiAlH4+MgBr2 organic solvent electrolyte, and the surface morphology, composition, structure, thickness, adhesion and corrosion resistance of aluminum-magnesium alloy coatings were observed and determined. The results show that the deposited aluminum-magnesium alloy coating is smooth, uniform and compact. The component of magnesium exists in the coating with Al-Mg solid solution and forms in the structure of (200) orientation. With increasing current density, the magnesium content, lattice parameter and thickness of coatings rise linearly. Al-Mg alloy coatings have a good adherent to the substrate (larger than 50 N), and have a high corrosion resistance in 3.5% NaCl solution. The deposition rate, adhesion force and corrosion resistance of aluminum-magnesium alloy coating are greater than that of pure aluminum coating under the same electro-deposited condition. The optimum current density for Al-Mg alloy coatings in organic solvent electrolyte is ranged from 0.75 to 1.50 A/dm2.
Key words: Al-Mg alloy; electroplating; organic solvent electrolyte; microstructure; corrosion resistance
