Inhibitor effects of sodium benzoate on corrosion resistance of Al6061-B4C composites in NaCl and H3BO3 solutions. (2nd December 2016)

• Record Type: Journal Article
• Authors: Rafi-ud-din, ; Shafqat, Q A; Shahzad, M; Ahmad, Ejaz; Asghar, Z; Rafiq, Nouman; Qureshi, A H; Syed, Waqar adil; Pasha, Riffat asim
• Is Part Of: Materials research express. Volume 3:Number 12(2016)
• Publication Date: 2016-12-02
• Subjects: metal matrix composites -- sodium benzoate -- electrochemical techniques -- corrosion inhibition; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/3/12/126501
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: Sodium benzoate (SB) is used for the first time to inhibit the corrosion of Al6061-B4 C composites in H3 BO3 and NaCl solutions. Al6061100− x – x wt% B4 C ( x = 0, 5, and 10) composites are manufactured by a powder metallurgy route. The corrosion inhibition efficiency of SB is investigated as a function of the volume fractions of B4 C particles by using potentiodynamic polarization and electrochemical impedance techniques. Without the use of an inhibitor, an increase of the B4 C particles in the composite decreases the corrosion resistance of Al6061-B4 C composites. It is found that SB is an efficient corrosion inhibitor for Al6061-B4 C composites in both investigated solutions. The corrosion inhibition efficiency of SB increases with an increase in B4 C content. Since SB is an adsorption type inhibitor, it is envisaged that an extremely thin layer of molecules adsorbs onto the surface and suppresses the oxidation and reduction. It is found that the inhibitor effect of SB is more pronounced in a H3 BO3 environment than in NaCl solution. Further, the mechanism of corrosion inhibition by SB is illustrated by using optical and scanning electron microscopy of corroded samples. It is found that the adsorption of benzoate ions on the Al surface and its bonding with Al 3+ ions forms a hydrophobic layer on top of the exposed Al surface, which enhances the protection against dissolved boride ions.