ABSTRACT Scandium addition significantly alters the corrosion resistance and mechanical strength of Al-3 Mg alloys. The addition of 0.3% - 0.4% scandium with 0.14% zirconium has a beneficial effect on the corrosion resistance of the alloy under smoothly stirred condition. Addition of 0.3% Sc significantly suppresses corrosion under dynamic flow conditions. It also creates an optimal strengthening effect on the alloys. The corrosion resistance is attributed to the strong passive layer of Sc2O3 formed on the ultrafine coherent precipitates of Al3Sc. A strong evidence of the pinning of grain bounda-ries by coherent nano Al3Sc precipitates is responsible for the strengthening effect.
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nullZ. Ahmad, A. Aleem and M. Abbas, "Effect of Scandium Doping on The Corrosion Resistance and Mechanical Behavior of Al-3Mg Alloy in Neutral Chloride Solutions," Materials Sciences and Applications, Vol. 2 No. 4, 2011, pp. 244-250. doi: 10.4236/msa.2011.24031.
 W. T. Tack, “Aluminum-Scandium Alloys,” US Patent 5,597,529, 1997.
 M. E. Drits, N. T. Turkina and E. S. Kander, “Structure and Mechanical Properties of Aluminum-Scandium Alloys,” In: Rare Earth Metals in Non Ferrous Alloys (Russian), Nauko, Moscow, 1975.
 M. E. Drits, L. S. Toropova and Y. U. G Bykov, “Effect of REM on the Mechanical Properties of Aluminum Alloys Containing 6.5% Mg,” Metal Science and Heat Treatment, Vol. 22, No. 10, 1980, pp. 35-37.
 M. E. Dritz, S. G. Pavlenko, L. S. Toropova, Y. G. Bykov and L. B. Ber, “Mechanism of Scandium Effect to Increasing Strength and Thermal Stability of Al-Mg Alloys,” Doklady Akademii Nauk, SSSR, Vol. 257, No. 2, 1981, pp. 353-356.
 M. Song, Y. H. He and S. F. Fang, “Effects of Zr Content on the Yield Strength of an Al-Sc Alloy,” Journal of Materials Engineering and Performance, Vol. 20, No. 3, 2010, pp. 377-381.
 B. Irving, “Scandium Places Aluminum Welding on a New Plateau,” Welding Journal, Vol. 76, No. 7, 1997, pp. 53-57.
 R. R. Sawtell and C. L. Jensen, “Mechanical Properties and Microstructures of Al-Mg-Sc Alloys,” Metallurgy and Materials Transactions, Vol. 21, No. 1, 1990, pp. 421-430. doi:10.1007/BF02782422
 M. E. Dritz, L. B. Ber, Y. G. Bykov, L. S. Toropova and G. K. Anastaseva, “Ageing Alloy Al-0.3 at.% Sc,” Physics of Metal and Metallography, Vol. 57, 1984, pp. 118-126.
 V. L. Elagin, I. V. Zakharov and T. D. Rostova, “Scandium-Alloyed Aluminum Alloy,” Nonferrous Metals and Alloys, Vol. 34, No. 1, 1992, pp. 37-45.
 N. Blake and M. A. Hopkins, “Constitution and Age Hardening of Al-Sc Alloys,” Journal of Material Science, Vol. 20, 1985, pp. 2861-2867. doi:10.1007/BF00553049
 Z. Ahmad, “The Properties and Application of Scandium-Reinforced Aluminum,” JOM Journal of the Minerals, Metals and Materials Society, Vol. 55, No. 2, 2003, pp. 35-39.
 ASTM G3-72, “Laboratory Immersion Testing, Book of Annual Standards,” ASTM, Columbus, 2002.
 ASTM G5-87, “Recommended Practice for Making Potentiostatic and Potentiodynamic Polarization Measurements, Annual Book of Standards,” ASTM, Columbus, 2002.
 ASTM G5-91, “Recommended Practice for Making Polarization Resistance Measurements, Annual Book of Standards,” ASTM, Columbus, 2002.
 ASTM G61-86, “Conducting Cyclic Potentiodynamic Polarization Measurements for Localized Corrosion, Annual Book of Standards,” ASTM, Columbia, 2002.
 Z. Ahmad, “Effect of Velocity on the Corrosion Behavior of Al-3Mg in North Sea Water,” Métaux-Corrosion-Industrie, Metaux, 1982.
 K. N. Nisanloglu and H. Holtan, “Correlation of the Open-Circuit and Electrochemical Measurements for the Pitting Corrosion of Aluminim in Chloride Media,” Metarials and Corrosion, Vol. 30, No. 2, 1979, pp. 105-113.
 N. V. Yvazovikina, N. A. Krapivka and S. S. Ponomarev, “Kinetics and Mechanism of Scandium Dissolution in Sulfuric Acid Solutions,” Russian Journal of Electrochemistry, Vol. 33, No. 9, 1997, pp. 950-957.
 N. V. Yvazovikina, S. S. Ponomarev and N. A. Krapivka, “Anode Dissolution and pasSivation D-Transition Metals and Their Alloys in Aqueous Solutions of Electrolytes 2000 hrs,” Joint International Meeting of Electrochemical Society, Paris, Vol. 97-2, No. 554, 1997, p. 663.
 M. E. Drits, E. J. Kadner and T. V. Dobats, “Scandium-Aluminum Interactions in the Al-Rich Side of the Al-Sc System,” Russian Metallurgy, Vol. 4, 1973, p. 152.