Effect of Scandium Doping on The Corrosion Resistance and Mechanical Behavior of Al-3Mg Alloy in Neutral Chloride Solutions

Zaki Ahmad, Abdul Aleem B. Aleem, Mohammad Abbas

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DOI: 10.4236/msa.2011.24031                

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.

Keywords

Corrosion, Polarization, Passive, Pitting, Strengthening Effect, Pinning, Grain Boundaries, Precipitates, Films, Passive Layers

Conflicts of Interest

The authors declare no conflicts of interest.

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