Laser generated neutron source for neutron resonance spectroscopy

Copyright 2010 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physics of Plasmas, 17(10), 100701, 2010 and may be found at http://dx.doi.org/10.1063/1.348421

Time dependent debonding of aluminum/alumina interfaces under cyclic and static loading

The structural integrity of oxide/metal interfaces is important in many applications

Deformation of nanocrystalline materials at ultrahigh strain rates – microstructure perspective in nanocrystalline nickel

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