INVESTIGADORES
BRINGA Eduardo Marcial
artículos
Título:
Atomistic mechanism of shock-induced void collapse in nanoporous metals
Autor/es:
P. ERHART; E.M. BRINGA; M. KUMAR; K. ALBE
Revista:
PHYSICAL REVIEW B
Editorial:
AMER PHYSICAL SOC
Referencias:
Año: 2005 vol. 72 p. 52104 - 52108
ISSN:
1098-0121
Resumen:
We have investigated the microstructural changes in ductile porous
metals during high pressure-high strain rate loading employing atomistic
simulations and explored their relation to recent experiments on
polycrystalline copper samples. Molecular-dynamics simulations of shocks
in porous, single-crystal samples show the formation of nanograins due
to localized massive plastic deformation induced by the presence of
voids. In the process of grain formation the individual voids serve as
dislocation sources. The efficiency of these sources is further enhanced
by their collective interaction which eventually leads to very high
dislocation densities. In agreement with experimental studies, the
simulations display a temporal delay of the particle velocity in
comparison to perfectly crystalline samples. This delay increases with
porosity. Our results point towards the importance of void-void
interactions and collective effects during dynamic loading of porous
materials.