J. Phys. IV France
Volume 110, September 2003
Page(s) 851 - 856

J. Phys. IV France
110 (2003) 851
DOI: 10.1051/jp4:20020800

Laser shock compression of copper monocrystals: Mechanisms for dislocation and void generation

M.A. Meyers1, M.S. Schneider1, B.K. Kad1, V.A. Lubarda1, F. Gregori2, D.H. Kalantar3 and B.A. Remington3

1  University of Catifornia, San Diego, La Jolla, CA 92093, U.S.A.
2  University of Paris 13, France
3  Lawrence Livermore National Laboratory, Livermore, CA 94450, U.S.A.

Copper with two orientations ([001] and [134]) was subjected to high intensity laser (energy levels of 40-300 J; energy densities of 15-70 MJ/m 2 and durations below 10 ns). The defects created are characterized by transmission electron microscopy. An orientation-dependent threshold stress for twinning is observed. The results are rationalized in terms of a criterion in which slip and twinning are considered as competing mechanisms. A constitutive description is applied to the two orientations, incorporating both slip and twinning. The predictions are in agreement with experiments. The threshold stress for twinning in the [001] orientation is 20-40 GPa, whereas the one for the [134] orientation is 40-60 GPa. The threshold stress is calculated, considering the effect of shock heating. The constitutive description provides a rationale for the experimental results; the calculated thresholds are 18 GPa for [001] and 25 GPa for [134]. A mechanism for void generation and growth based on the emission of geometrically necessary dislocations is proposed and analytically formulated.

© EDP Sciences 2003