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

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 degrees C) and aging treatment (200 degrees C) were explored to improve coatings adhesion and hardness, and to maintain corrosion resistance 420 degrees C treatment produced a beta-phase (Mg17Al12) enriched two-phase coating whilst treatment at 200 degrees C leads to a tri-layer structure rich in gamma-phase (Mg2Al3) The 200 degrees C treatment was shown to be most effective for corrosion resistance eradicating water reduction as the principal cathodic reaction and increasing surface hardness (C) 2010 Elsevier Ltd All rights reserved