GS01 Corrosion Property of Die Cast Aluminum Alloy under Tensile Stress in Sodium Chloride Solution
Details
Effect of tensile stress on the corrosion potential of high pressure die cast aluminum alloy was examined by the tensile test in a corrosive environment with the electrochemical measurement. The aluminum alloy has an oxide film as a corrosion barrier, but the oxide film may partially break by the mechanical stress and the damage leads to a local corrosion such as pitting corrosion by the effect of local cell. To qualitatively evaluate the strength of corrosion fatigue or stress corrosion cracking, the effect of stress on the electrochemical property has to be clarified. The spontaneous potential difference was measured by the three-electrode system during the tensile test, and the relationship between the spontaneous potential and the tensile stress was evaluated. The results showed that the spontaneous potential certainly decreased within the elastic region and saturated after the yielding. The effect of casting skin was also examined, and the spontaneous potential decreased due to the deletion of the casting skin.
