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Effect of Scandium Doping on The Corrosion Resistance and Mechanical Behavior of Al-3Mg Alloy in Neutral Chloride Solutions
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Materials Sciences and Applications·Volume 02 (2011)·Pages 244–250·Published 22 March 2011·DOI10.4236/msa.2011.24031
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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 Sc<sub>2</sub>O<sub>3</sub> formed on the ultrafine coherent precipitates of Al<sub>3</sub>Sc. A strong evidence of the pinning of grain bounda-ries by coherent nano Al3Sc precipitates is responsible for the strengthening effect.
KeywordsCorrosionPolarizationPassivePittingStrengthening EffectPinningGrain BoundariesPrecipitatesFilmsPassive Layers
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