THE PARTIAL ELECTROCHEMICAL MEMORY EFFECT OF AA 5083-H321 ALLOY SURFACE, AFTER SOLUTION HEAT TREATMENT: INFLUENCE OF PRECONDITIONS THERMO-MECHANICAL TREATMENTS - Zazi, Nacer; Chopart, Jean-Paul; Bouabdallah, Ahcène; Meziani, Hakima (2022)
Corrosion behavior of AA5083-H321 aluminum alloy sheet in 3 wt. % NaCl solution, microstructure and hardness, were investigated. The material has undergone during the industrial manufacturing process a hot and a cold rolling followed by industrial stabilization, and a laboratory annealing of 90 min maintenance at 420°C followed by air-cooling. The results show a difference of polarization resistance and corrosion potential, in the first hour and after two weeks of corrosion, between rolled face and perpendicular face. After 360 hours of corrosion, the electrochemical impedance spectroscopy curves exhibit a dissimilarity of charge transfer resistance and double layer capacitance between the two surfaces. The obtained microhardness and hardness values of the surfaces are almost the same. Size, fraction, shape and distribution of intermetallic particles of rolled face are different to those of perpendicular face. We attribute the difference of the electrochemical properties, which are not completely restored after solution heat treatment, to a partial memory effect.
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