Grain structure evolution in a 6061 aluminum alloy during hot torsion

The grain structure development of 6061 aluminum alloys deformed at elevated temperatures in torsion is presented here and related to industrial processing scenarios. Samples of a 6061 aluminum alloy representing two variations in chemistry have been studied at different values of effective strain, ɛeff., strain rate, ε˙, and temperature, T. Rapid quenching techniques were implemented to ensure preservation of the deformed microstructure after deformation ceased. It was determined that at effective torsion strains greater than 2.5, a fine, equiaxed grain structure develops and may be related to a type of dynamic recrystallization (DRX). The final grain size increases with increasing deformation temperature.