Effect of the Thermo-Mechanical Treatment on IGC Susceptibility of AA 5083 Alloy

Abstract

This work reports on the effect of thermo-mechanical treatment on IGC susceptibility of the AA 5083 alloy. Specimens underwent varied amount of cold work and final annealing was conducted at 240°C. Extent of the cold work affected the IGC susceptibility of the alloy significantly. Microstructure characterization showed that depending on the amount of the cold work different deformation substructure was created, which, in turn, influenced morphology of precipitated β-phase (Al3Mg2). Formation of continuous film of the β-phase at the grain boundaries was observed in the specimens that were subjected to lower degree of the cold work and which were IGC susceptible. Better corrosion resistance characterized the specimens that underwent higher degree of the cold work (over 30-40%) due to β-phase precipitation in the form of discrete particles at the grain boundaries and in grain interiors.