Testing the Limits of Small Scale Plasticity with Thin Wires in Torsion

Abstract

ABSTRACTTorsion experiments on 50μm diameter Cu wires are reported, using the load/unload method and a gauge length of 1m to obtain torsional strain sensitivity better than unity microstrain. The experiments are able to resolve reversible and irreversible deformation at such very low strains. Plastic deformation, dislocation creep and the Bauschinger effect are easily observed at room temperature and at about 300°C, both in the low-strain regime where it is unlikely that dislocation sources are activated, and at higher plastic strain.