INVESTIGADORES
BRINGA Eduardo Marcial
artículos
Título:
Deformation of nanocrystalline materials at ultrahigh strain rates microstructure perspective in nanocrystalline nickel
Autor/es:
Y.M. WANG; E.M. BRINGA; M. VICTORIA; A. CARO
Revista:
JOURNAL DE PHYSIQUE IV
Editorial:
EDP SCIENCES
Referencias:
Año: 2006 vol. 134 p. 915 - 920
ISSN:
1155-4339
Resumen:
Nanocrystalline materials with grain sizes smaller
than 100 nm have attracted extensive research in the past decade.
Due to their high strength, these materials are good candidates for
high pressure shock loading experiments. In this paper, we
investigated the microstructural evolutions of nanocrystalline
nickel with grain sizes of 10-50 nm, shock-loaded in a range of
pressures (20-70 GPa). A laser-driven isentropic compression
process was applied to achieve high shock-pressures in a timescale
of nanoseconds and thus the high-strain-rate deformation of
nanocrystalline nickel. Postmortem transmission electron microscopy
(TEM) examinations reveal that the nanocrystalline structures
survive the shock deformation and that dislocation activity is the
prevalent deformation mechanism when the grain sizes are larger than
30 nm, without any twinning activity at twice the stress threshold
for twin formation in micrometer-sized polycrystals. However,
deformation twinning becomes an important deformation mode for 10-20
nm grain-sized samples.