(天津大學(xué) 材料科學(xué)與工程學(xué)院， 天津 300072)
摘 要: 利用AlCl3+LiAlH4+MgBr2有機(jī)溶劑體系在碳鋼基體上電沉積出Al-Mg合金鍍層， 并對不同沉積電流密度下Al-Mg鍍層的表面形貌、 成分、結(jié)構(gòu)、 厚度、 結(jié)合力和耐蝕性進(jìn)行了研究。 結(jié)果表明： 沉積出的鋁鎂合金鍍層表面光滑、 均勻、 致密； 膜層中的鎂含量隨沉積電流密度的增加而增大， 且以Al-Mg固溶體形式存在， 并按（200）面的結(jié)構(gòu)生長； 隨沉積電流密度的增加，鋁鎂合金鍍層的厚度與晶格常數(shù)呈線性增大； 在3.5% NaCl溶液中的耐蝕性呈先增大后減小的規(guī)律； Al-Mg鍍層與碳鋼基體的結(jié)合力良好， 均大于50 N； Al-Mg鍍層的沉積速率、 結(jié)合力和耐蝕性均高于相同沉積條件下的純鋁鍍層； Al-Mg合金鍍層沉積的最佳電流密度為0.75～1.50 A/dm2。
關(guān)鍵字: Al-Mg合金； 電鍍； 有機(jī)溶劑體系； 組織結(jié)構(gòu)； 耐蝕性
（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
