The Open Corrosion Journal · 2010 · 30 citations · 11 references
Natural SciencesMaterials EngineeringMaterials ScienceCorrosion ScienceElectrochemistryMetallic MaterialsCorrosion EngineeringCorrosion MechanismsCorrosion ResistanceCorrosion TestingElectrochemical CorrosionMetalsAluminum AlloysCorrosion BehaviorCorrosion Of Aluminum AlloysCorrosion PotentialElectrochemical BehaviorElectrochemical MechanismsOpen-circuit PotentialPolarization Resistance
The role of Mg 2 Si in the electrochemical behavior of Al-Si-Mg aluminum alloys has been studied using four experimental aluminum alloys with variations in the Si/Mg molar ratio (A1-0.12, A2-0.49, A3-0.89, A4-1.05), in neutral aerated 0.1M NaCl solutions. Accordingly, the corrosion potential in open circuit (E oc ) and polarization resistance (Rp) were measured. Results show that the augment in Si/Mg molar ratio increases the presence of Mg 2 Si intermetallic phase. During immersion tests in neutral aerated chloride solutions the anodic activity of the Mg 2 Si intermetallic decreased rapidly, as indicated by a fast ennoblement of open circuit potential. After the immersion period (7 days), higher Rp values for alloys A3 and A4 (21 and 26 K cm 2 , respectively) as compared to those for alloys A1 and A2 (5 and 10 K cm 2 , respectively), suggest a greater corrosion resistance in Cl -containing environments for alloys A3 and A4.
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