CORROSION BEHAVIOR OF BARE AZ31 ALLOY AND MG (OH)2 @ AZ31 ALLOY IN THE PRESENCE OF INHIBITORS

In this work, the 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6] ionic liquid and ethylenediamine [ED] were employed as corrosion inhibitors for AZ31 magnesium alloy in 3.5 wt.% NaCl electrolyte. The adsorption of the inhibitors on the surface of AZ31 alloy is the main mechanism observed for both the inhibitors. The potentiodynamic polarization curves (Tafel plots) of bare AZ31 in the presence of ED and [bmim][PF6] inhibitors reveal that the ionic liquid 1-butyl-3- methylimidazolium hexafluorophosphate shows more noble shift in potential and lower corrosion rates than ethylenediamine. The corrosion resistance, which is realized from electrochemical impedance analysis, also shows the increased corrosion resistance in 3.5 wt% NaCl as follows: Bare AZ31< ethylenediamine < 1-butyl-3-methylimidazolium hexafluorophosphate