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 -phase (Al 3 Mg 2 ). Formation of continuous film -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 -phase precipitation in the form of discrete particles at the grain boundaries and in grain interiors.

Influence of annealing temperature on sensitisation behaviour and corrosion properties of an Al‐6.8 wt% Mg alloy

“…Besides Mg content, key factors controlling the precipitation of the β‐(Al 3 Mg 2 ) phase in the Al–Mg alloys are considered to be sensitisation temperature and time; their increase increases fraction and continuity of the grain boundary β‐(Al 3 Mg 2 ) phase . However, a thermo‐mechanical treatment has an influence on β‐(Al 3 Mg 2 ) phase precipitation and can alter corrosion response of Al–Mg alloys . Precipitation of the β‐(Al 3 Mg 2 ) phase appears to be more advanced in deformed than in recrystallised microstructure of AA 5083 alloy‐type materials that underwent similar sensitisation treatment.…”