Effect of strain rate and deformation temperature on strain hardening and softening behavior of pure copper
(Southwest Technique and Engineering Institute, Chongqing 400039, China)
Abstract: The effects of the deformation temperature and the strain rate on the hot deformation behavior of pure copper were investigated based on compression tests. The expressions of strain hardening rate, dynamic recrystallization critical stress, saturated stress, dynamic recovery volume fraction and dynamic recrystallization volume fraction were determined. According to the processing map, the instability regions occur in regions of 400-450 °C, 0.001-0.05 s-1 and 450-750 °C, 0.05-1 s-1. The deformation mechanism in the stability region is dynamic recrystallization. The flow stress was predicted. The results also show that the true stress–true strain curves predicted by the extracted model are in good agreement with the experimental results.
Key words: copper; hot compression deformation; strain hardening; strain softening