151. Dynamic recrystallization and recovery during high-pressure torsion : Experimental evidence by torque measurement using ring specimens
- Author
-
Zenji Horita, Kaveh Edalati, Tadahiko Furuta, and Shigeru Kuramoto
- Subjects
Materials science ,Homologous temperature ,Mechanical Engineering ,Metallurgy ,Torsion (mechanics) ,Recrystallization (metallurgy) ,chemistry.chemical_element ,Twin ,Stacking fault energy ,Flow stress ,Condensed Matter Physics ,Copper ,Grain size ,Severe plastic deformation (SPD) ,Condensed Matter::Materials Science ,chemistry ,Mechanics of Materials ,Dynamic recrystallization ,General Materials Science ,Dislocation ,Softening ,Aluminum - Abstract
Several pure metals exhibit softening when imparting large strains at room temperature. This study investigates the nature of this strain softening. Torque measurements during high-pressure torsion using ring specimens, which appear to be more suitable than disk specimens for the evaluation of the strain response on the in situ flow stress, suggest that the softening in aluminum occurs mainly by dynamic recrystallization and recovery, whereas no appreciable dynamic softening occurs in copper. The softening in aluminum is associated with decreasing the dislocation density and increasing the grain size and missorientation angles, whereas copper exhibits ultrafine grains of higher dislocation density and few nanotwins. A significant static recrystallization is detected in HPT-processed pure copper by argon irradiation during ion milling.
- Published
- 2013