Pyrazole acylhydrazone Schiff bases as magnesium alloy corrosion inhibitor: Synthesis, properties and mechanism investigation

Four novel pyrazole acylhydrazone Schiff bases were synthesized and tested as corrosion inhibitors for AZ91D in 0.5 wt.% NaCl solution. These inhibitors had good corrosion inhibition performance on Mg alloy. The results show that the aryl ring (Ar1) and aryl heterocyclic ring(Ar2) in the inhibitor molecules can improve the rigidity of the molecular structure and facilitate the adsorption of inhibitor molecules on the surface of magnesium alloy. The surface morphologies of magnesium alloy were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The possible inhibition mechanism was studied by X-ray photoelectron spectroscopy (XPS). The results indicated that the corrosion inhibitor molecules deposited on the surface of AZ91D Mg alloy by cyclic voltammetry can form an effective protective film and improved the inhibition efficiency (92.2%) of corrosion inhibitors.