Impact compression behavior of FCC metals with pre-torsion strains

This paper investigates the effect of non-proportional pre-straining path o n flow behavior of FCC metals at impact compression, where reversed torsion strain is introduced following 10% pre-torsion. Two kinds of FCC metals, A l and Cu, are employed to also examine the material dependency. Experimenta l results demonstrate that significant interaction exists between strain hi story and strain rate effects, which is strongly material dependent. The re versed torsion temporarily reduces strain history effect for Al. The trend is shown to be described qualitatively by analysis based on the crystalline plasticity theory where newly proposed back stress model considering pilin g-up behavior of dislocations is introduced. (C) 1999 Elsevier Science S.A. All rights reserved.