2-Hydroxy-4-methoxy-acetophenone as an environment-friendly corrosion inhibitor for AZ91D magnesium alloy

• Paeonol effectively inhibits the corrosion of AZ91D Mg alloy in 0.05 wt.% NaCl solution.
• The best inhibition is achieved with 50 ppm paeonol addition.
• Paeonol chelates with Mg and makes the surface film more compact and protective.

The inhibition behavior of 2-hydroxy-4-methoxy-acetophenone (paeonol) as an environment-friendly corrosion inhibitor for AZ91D magnesium alloy was investigated in 0.05 wt.% NaCl solution by means of polarization curve, AC impedance, weight loss measurement, scanning electron microscopy, Fourier transformation infrared spectroscopy, ultraviolet analysis, and computer molecular simulation. The results show that paeonol can inhibit the corrosion of AZ91D. The maximum inhibition efficiency is achieved when paeonol concentration is 50 ppm by weight in this study. It is proposed that paeonol chelates with Mg to form a paeonol-Mg complex mixing with the original Mg(OH)2 film on the surface to inhibit the anodic dissolution of AZ91D.