Study the Corrosion behavior of AA7051 Aluminum alloy at different temperatures and inhibitor concentration in Acidic medium

Abstract

This study will be investigating acidic corrosion of AA7051 alloy at a different temperature, and introduces milk thistle aqueous extract as a new and widely available green corrosion inhibitor. The electrochemical methods were used to measure weight loss, penetration loss, corrosion inhibition efficiency and other parameters. The data substituted in Langmuir adsorption isotherm as well as in kinetic equations. The finding exhibit high corrosion inhibition efficiency at 0.5g/L of milk thistle extract and the efficiency rose from around 72% at 293K to just over 86% at 333K. Langmuir model linear regression coefficient ( =0.98) and the slight change in corrosion potential refer to mixed-type inhibitor attach to the surface by chemisorption. FTIR spectra for crude extract supported by literatures shows the molecular structure of the main component of milk thistle extract and exhibit the O-H group as a major group participate in adsorption.