J. Phys. IV France 01 (1991) C3-11-C3-17
HIGH STRAIN, HIGH STRAIN-RATE DEFORMATION OF COPPERM.A. MEYERS1, L.W. MEYER2, K.S. VECCHIO1 and U. ANDRADE1
1 Department of Applied Mechanics and Engineering Sciences, University of California, San Diego, La Jolla, CA 92093-0411, U.S.A
2 Fraunhofer Institut für Angewandte Materialforschung, Bremen, Germany
Shock-hardened polycrystalline copper was subjected to high strains (γ ∼ 5) at high strain rates (γ' ∼ 104 s-1) using a stepped specimen in a Hopkinson bar. Microstructural analysis by transmission electron microscopy revealed that the highly deformed region consisted of very small grains (∼ 0.1 µm) with a low dislocation density. These results are discussed in terms of dynamic recrystallization, which is enabled by the adiabatic temperatures rise associated with plastic deformation. This dramatic microstructural refinement enables a thermomechanical response that may lead to a stable plastic deformation in tension.
© EDP Sciences 1991