Electrodeposition of chemically and mechanically protective Al-coatings on AZ91D Mg alloy

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• 作者：Haiyan Yang ; Xingwu Guo ; Guohua Wu ; Wenjiang Ding ; Nick Birbilis
• 关键词：A. Magnesium ; A. Metal coatings ; A. Intermetallics ; B. Polarization ; C. Electrodeposited films
• 刊名：Corrosion Science
• 出版年：2011
• 出版时间：January 2011
• 年：2011
• 卷：53
• 期：1
• 页码：381-387
• 全文大小：1310 K

文摘

Electrodeposition of aluminium coatings upon AZ91D in aluminum chloride/1-ethyl-3-methylimidazolium chloride ionic liquid was achieved. Post-plating heat treatment processes compatible with AZ91D solution treatment (420 °C) and aging treatment (200 °C) were explored to improve coatings adhesion and hardness, and to maintain corrosion resistance. 420 °C treatment produced a β-phase (Mg₁₇Al₁₂) enriched two-phase coating; whilst treatment at 200 °C leads to a tri-layer structure, rich in γ-phase (Mg₂Al₃). The 200 °C treatment was shown to be most effective for corrosion resistance, eradicating water reduction as the principal cathodic reaction and increasing surface hardness.