A synergistic anti-corrosion effect of longan residue extract and sodium dodecylbenzenesulfonate composition on AZ91D magnesium alloy in NaCl solution

Addition of inhibitor is an efficient and feasible method to delay the corrosion of magnesium alloys. Longan residue extract (LRE) is a promising inhibitor with the sustainable and abundant advantages. However, the inhibition efficiency of LRE is only 80.01% in NaCl solution, which would not supply the efficient protection for the Mg alloys. The other inhibitor, sodium dodecylbenzenesulfonate (SDBS), is employed to refine the anti-corrosion performance. The anti-corrosion performance of hybrid inhibitor is investigated by electrochemical measurements, scanning electron microscopy (SEM), X-ray diffractometer (XRD), and atomic force microscopy (AFM). The inhibition efficiency can be remarkably increased to 92.15% due to the synergistic effects of LRE and SDBS. The anti-corrosion performance would be further increased to 95.67% if the Mg alloys are soaked in the solution including the hybrid inhibitors for 12 h. The present studies explore a new and efficient inhibitor for Mg alloys and afford a feasible strategy to utilise the agriculture waste.