Preliminary Study on Dimocarpus Longan Peel as Inhibitors for the Pitting Corrosion of 5052-O and 6061-O Aluminium Alloys in Artificial Brine Solution

The effect of dimocarpus longan peel extract onthe pitting corrosion of 5052-O and 6061-O aluminiumalloys in an aqueous solution of artificial brine has beenstudied employing open circuit potential (OCP) and cyclicpotentiodynamic polarization techniques. Moreover, surfacestudies such as scanning electron microscope (SEM) andenergy dispersive spectroscopy (EDS) were also applied. Theaddition of that extract increases pitting potential (Epit) bothaluminium alloys, increasing the resistance of pittingcorrosion both them. On the other hand, the resistance ofpitting corrosion on 6061-O alloy was higher than that of5052-O alloy during the addition of that extract. Theaddition of that extract also shifts OCP towards to positivepotentials both alloys, which indicates the formation of apassive surface layer on the surface of alloys. On the basis ofresults, the appearance of pit shows on the surface of 5052-Oalloy due to the presence Fe-enrich phase, compared to thatof 6061-O alloy International Journal of Engineering Research,2017, Volume No.6, Issue No.1 0, pp : 433-436