Atomistic simulation of an f.c.c./b.c.c. interface in NiCr alloys

• Published in: Acta materialia 1997-11, Vol.45 (11), p.4415-4421
• Main Authors: Chen, J.K., Farkas, D., Reynolds, W.T.
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Martensitic transformations; Materials science; Metals. Metallurgy; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/S1359-6454(97)00159-6

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 oriented in a Kurdjumov-Sachs orientation relationship, and the interface considered is the (1 2̄ 1) f habit plane adopted by precipitate laths of the b.c.c. phase. The interfacial energy and coherent strain energy at 0 K are calculated for boundaries between an f.c.c. NiCr solid solution and b.c.c. Cr. The calculated interfacial energy varies from 216 mJ/m 2 when the f.c.c. phase is pure Ni to 200 mJ/m 2 when 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 interfacial energy is attributed to the structural difference across the f.c.c./b.c.c. boundary, and the chemical contribution to the energy is estimated to be less than 20% of the total energy. The value of the calculated energies and the widespread occurrence of the (1 2̄ 1) f habit plane in a variety of alloy systems indicate this boundary orientation has a relatively low interfacial energy.