Abstract:
Aluminium alloy type 5083 or AA5083 is known for exceptional performance in extreme
environments. AA5083 shows an excellent corrosion resistance mostly in seawater and
industrial chemical environment. Nowadays, corrosion is entrenched in maritime industry
where the ship plate undergoes corrosion and it depends on the different environment. As
a remedy, natural inhibitor was used to overcome this problem. This study used plant
extract which is henna (Lawsonia Inermis). Henna was extracted with ethanol as solvent
by using rotary evaporator (Rotavap ). Low concentration of henna which is 100, 200,
300, 400 and 500ppm was used. The characterization of the corrosion was performed by
using potentiodynamic polarization (PP), weight loss, electrochemical impedance
spectroscopy (EIS), fourier transform infrared spectroscopy (FTIR) and scanning electron
microscope (SEM). The percentage of inhibition efficiency (IE %) was calculated by
using equation and this study showed the corrosion rate increase by decreasing
concentration of the henna extract. This extract is believed to form a surface layer as it
protects AA5083 from reacting to the environment.
