Computer simulation study of the effects of copper precipitates on dislocation core structure in ferritic steels

Conference · Sat Nov 01 04:00:00 EST 1997

OSTI ID:541150

Harry, T; Bacon, D J ^[1]

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1. Univ. of Liverpool (United Kingdom). Dept. of Materials Science and Engineering

The small, coherent BCC precipitates of copper that form during fast neutron irradiation of ferritic steels are an important component of in-service irradiation hardening. Many-body interatomic potentials for the Fe-Cu alloy system have been developed and used to simulate the atomic structure of the 1/2<111> screw dislocation in both pure {alpha}-iron and the metastable BCC phase of copper. In iron, the core has the well-known 3-fold form of atomic disregistry. In BCC copper, however, the core structure depends on the lattice parameter. At the metastable equilibrium value, the core is similar to that in iron, but as the lattice parameter is reduced, as in a precipitate, the core becomes delocalized by transformation of the copper. Simulation of dislocated crystals containing precipitates shows that the extent of this effect depends on precipitate size. The energy changes indicate a significant dislocation pinning effect due to this dislocation-induced precipitate transformation process.

• OSTI ID: 541150
• Report Number(s): CONF-961202--; ISBN 1-55899-343-6
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
36 MATERIALS SCIENCE
CRYSTAL DEFECTS
EMBRITTLEMENT
FERRITIC STEELS
MICROSTRUCTURE
PHYSICAL RADIATION EFFECTS
PRECIPITATION
RADIATION HARDENING
REACTOR MATERIALS