The development of a forming limit surface for 5083 aluminum alloy sheet

A custom mechanical stretching setup based on the Nakazima method was designed and built for testing sheet metals at elevated temperatures. Specimens from a fine-grained 5083 aluminum alloy sheet were deformed at various temperatures, spanning between those associated with warm forming (250°C) and hot forming (550°C). Circle grid analysis of the deformed specimens produced the forming limit curves at each of the covered temperatures, hence revealing the great influences of forming temperature on the material’s formability limits. Finally, all the curves were combined to construct a unique three-dimensional forming limit surface, which we present here as a more comprehensive map for describing material formability limits at wide-ranging temperatures.