Studies of Corrosion Inhibition Performance of Inorganic Inhibitors for Aluminum Alloy

Abstract

In this study, the behavior of sodium silicate (Na<inf>2</inf>SiO<inf>3</inf>), manganese sulfate monohydrate (MnSO<inf>4</inf>·H<inf>2</inf>O), and ammonium metavanadate (NH<inf>4</inf>VO<inf>3</inf>) as corrosion inhibitors for AA6061 aluminum alloy (Al) was investigated. The polarization resistance (R<inf>p</inf>) of the Al substrate immersed in 0.1 M NaCl solution was found to be 13 kΩ·cm2. In comparison, the R<inf>p</inf> of the Al substrate immersed in 0.1 M NaCl in the presence of Na<inf>2</inf>SiO<inf>3</inf>, Na<inf>2</inf>SiO<inf>3</inf>/MnSO<inf>4</inf>·H<inf>2</inf>O, and Na<inf>2</inf>SiO<inf>3</inf>/NH<inf>4</inf>VO<inf>3</inf> inhibitors was found to be 100, 133, and 679 kΩ·cm2, respectively. The best inhibition result was obtained when the mixture of the inhibitors was used with R<inf>p</inf> of 722 kΩ·cm2. The maximum percentage of the corroded area calculated from the scanning electron microscopy (SEM) images was found to be 5.7% for Al substrate immersed in 0.1 M NaCl, which decreased to 0.06% when the mixture of the inhibitors was used. The synergetic effects between the three inhibitors were studied, and the results illustrated that the combination of Na<inf>2</inf>SiO<inf>3</inf>, MnSO<inf>4</inf>·H<inf>2</inf>O, and NH<inf>4</inf>VO<inf>3</inf> provided the best corrosion inhibition properties for Al in aqueous NaCl environments. © 2025 by the authors.