Laalitha Liyanage Jeff Houze, Sungho Kim, M. A. Tschopp, Seong-Gon Kim, M. I. Baskes, M. F. Horstemeyer
Structural, elastic and thermal properties of cementite (Fe3C) were studied
using a newly developed Modified Embedded Atom Method (MEAM) potential for the
Fe-C alloy system. Previously developed Fe and C single element potentials were
used to develop the Fe-C alloy potential. The single element potential for C
correctly predicts both graphite and diamond as minimum energy structures. The
alloy potential was developed using a statistically based optimization scheme
to reproduce the heats of formation of element pairs in L12, B1 and cementite
structures, and the interstitial energies of C in bcc Fe. The stability of
cementite was investigated by molecular dynamics simulations at high
temperatures. The nine single crystal elastic constants for cementite were
obtained by computing total energies for strained cells. Polycrystalline
elastic moduli for cementite were calculated from the single crystal elastic
constants of cementite. Surface formation energies of (001), (010) and (100)
surfaces of cementite were also calculated. The melting temperature and
variation of specific heat and volume with respect to temperature, were
investigated by performing a two-phase (solid/liquid) simulation of cementite.
The predictions of the potential are in good agreement with first principles
calculations and experiments.
View original:
http://arxiv.org/abs/1202.3068
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