ROLE OF PLANT EXTRACTS FOR ALUMINUM CORROSION INHIBITION IN AGGRESSIVE ENVIRONMENT — STATE OF ART

Over the years, corrosion has resulted in causing damage to the structure in various engineering fields. Thus, corrosion has been treated as an environmental hazard. To control the metal corrosion in the aggressive medium, a corrosion inhibitor is used. The corrosion inhibitor, particularly an organic inhibitor, is expensive and toxic to the environment and also to living beings. Thus, the development of green corrosion inhibitors has been of great interest over a few decades. In a recent survey, the green inhibitor from plant extracts has proven to be cheap, non-toxic to the environment and is obtained from renewable sources. The study reports from the previous two decades are summarized in this review on the effect of the natural product as an agent against rusting for aluminum in aggressive media (mainly in acidic and alkaline media). This review focuses on the inhibiting effectiveness of different media (acid and alkaline) in various concentrations of plant extracts and the corrosion mechanism, particularly on aluminum. Moreover, the corrosion inhibition method used for the evaluation of the corrosion rate is presented. In addition, this paper reviewed the extract of diverse portions of the plants which are used as rust inhibitors for aluminum. The most often utilized procedures to assess corrosion inhibition were weight loss and electrochemical methods. This paper includes various studies like UV-Visible, FT-IR, XRD, SEM, EDX, AFM, and XPS that are conducted to confirm the corrosion inhibition characteristics of a plant.