الفهرس 
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Abstract
In the present study, Al-5wt.%Znalloywith differentactivation elements wereevaluated as a sacrificial anode for cathodic protection of carbon steel in artificial seawater.The anodes were fabricated from puremetals(Al, Zn, Bi, Sn, Sb and Te) using stir casting technique.
Optical microscope,SEM-EDS,XRD,XPS,immersiontestsanddifferentelectrochemical techniqueswere used.The results indicated thataddition ofSn (0.2 wt. %), Bi (0.2 wt. %), Sband Te from0.1 to 0.5 wt. % significantly reduced the grain size of Al-5Zn anode.The amount of Zn59Al41intermetallic precipitates was reduced with addition of Sn, Bi, Sb and Te into Al-5Zn anode while the solubility of Zn in α-Al matrix increased.On the other hand, Sband Te contents effectively inhibited the corrosion rate of investigated anodes.The corrosion rate of Al-5Zn-0.2Bi-0.2Sn was reduced from 12.9 mpy to 3.15 mpy with increasing Sb from 0.1 to 0.5 wt. %. The corrosion rate of Al-5Zn-0.2Bi-0.2Sn-0.4Sbwas reduced from 3.15mpy to 0.79mpy with increasing Te from 0.1 to 0.5 wt. %.
Further, thecathodic protection efficiency of mildsteel increased from 18.81% to 48.16% with increasing Sb from 0.1 to 0.5 wt. %. Incorporating Te from 0.1 to 0.5 wt. % for anode Al-5Zn-0.2Bi-0.2Sn-0.4Sb increased the cathodic Protection from 48.16% to 74.56%.