Identification of the metallurgical parameters explaining the corrosion susceptibility in a 2050 aluminium alloy

Abstract

The corrosion behaviour of a 2050 aluminium alloy was studied in a NaCl solution. The structure ofprecipitation did not fully explain the susceptibility to intergranular (in the -T34 state) and intragran-ular corrosion for the aged state (the -T8 state). A relationship between the nature of interfaces, thegrains characteristics (size, internal misorientation and orientation according to the plane exposed tothe electrolyte) on one hand and the corrosion susceptibility of the alloy on the other hand was clearlyestablished. Galvanic coupling between grains with different internal misorientations helped to explainthe intergranular corrosion susceptibility of the -T34 state