Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Atomic-scale simulations of nanocrystalline metals   Nanocrystalline metals, i.e. metals in which the grain size is in the
nanometer range, have a range of technologically interesting properties
including increased hardness and yield strength. We present atomic-scale
simulations of the plastic behavior of nanocrystalline copper. The simulations
show that the main deformation mode is sliding in the grain boundaries through
a large number of uncorrelated events, where a few atoms (or a few tens of
atoms) slide with respect to each other. Little dislocation activity is seen in
the grain interiors. The localization of the deformation to the grain
boundaries leads to a hardening as the grain size is increased (reverse
Hall-Petch effect), implying a maximum in hardness for a grain size above the
ones studied here. We investigate the effects of varying temperature, strain
rate and porosity, and discuss the relation to recent experiments. At
increasing temperatures the material becomes softer in both the plastic and
elastic regime. Porosity in the samples result in a softening of the material,
this may be a significant effect in many experiments.

13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio