Effects of additive Nal on electrodeposition of Al coatings in AlCl3-NaCl-KCl molten salts

• 作 者: Tianyu Yao Haiyan Yang Kui Wang Haiyan Jiang Xiao-Bo Chen Hezhou Liu Qudong Wang Wenjiang Ding
• 机 构: National Engineering Research Center of Light Alloy Net Forming, Shanghai Jiao Tong University, Shan
• 出 处: 化学科学与工程前沿
• 发表日期: 2021年1期
• 关键词: NaI additive electrodeposition molten salts Al coating

Effects of NaI as an additive on electrodeposition of Al coatings in AlCl3-NaCl-KCl (80-10-10 wt-％) molten salts electrolyte at 150℃ were investigated by means of cyclic voltammetry,chronopotentiometry,scanning electron microscopy and X-ray diffraction (XRD).Results reveal that addition of NaI in the electrolyte intensifies cathodic polarization,inhibits growth of A1 deposits and increases number density of charged particles.The electrodeposition of A1 coatings in the AlCl3-NaCl-KCl molten salts electrolyte proceeds via three-dimensional instantaneous nucleation which however exhibits irrelevance with NaI.Galvanostatic deposition results indicate that NaI could facilitate the formation of uniform A1 deposits.A compact coating consisting of Al deposits with an average particle size of 3 μm was obtained at a current density of 50 mA.cm-2 in A1Cl3-NaCl-KCl molten salts electrolyte with 10 wt-％ NaI.XRD analysis confirmed that NaI could contribute to the formation of Al coating with a preferred crystallographic orientation along (220) plane.