ATOMISTIC SIMULATION OF AN FCC BCC INTERFACE IN NI-CR ALLOYS/

The embedded atom method is applied to study the atomic structure and energy of an f.c.c./b.c.c. interface in Ni-Cr. The two phases are orie nted in a Kurdjumov-Sachs orientation relationship, and the interface considered is the (1(2) over bar1$)(f) habit plane adopted by precipit ate laths of the b.c.c. phase. The interfacial energy and coherent str ain energy at OK are calculated for boundaries between an f.c.c. Ni-Cr solid solution and b.c.c. Cr. The calculated interfacial energy varie s from 216 mJ/m(2) when the f.c.c. phase is pure Ni to 200 mJ/m(2) whe n the f.c.c. phase is Ni-50 at.% Cr. Atomic relaxations appear limited to atoms in contact with the interphase boundary. Most of the interfa cial energy is attributed to the structural difference across the f.c. c./b.c.c. boundary, and the chemical contribution to the energy is est imated to be less than 20% of the total energy. The values of the calc ulated energies and the widespread occurrence of the (1(2) over bar1$) (f) habit plane in a variety of alloy systems indicate this boundary o rientation has a relatively low interfacial energy. (C) 1997 Acta Meta llurgica Inc.