Article ID Journal Published Year Pages File Type
1469846 Corrosion Science 2011 7 Pages PDF
Abstract

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.

Research highlights►Al coatings upon AZ91D were achieved by novel electrodeposition employing IL. ►Advantages: minimum pretreatment, low cost and ability to coat complex shapes. ►Post plating heat treatment to the extent that Mg2Al3 is produced is tolerable. ►Intermetallic layers support water reduction and compromise corrosion resistance. ►Gateway paper to subsequent surface electrodeposition of alloyed layers.

Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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