Embedded atom study of dislocation core structure in Fe

• Published in: Scripta metallurgica et materialia Vol. 30; no. 7; pp. 921 - 925
• Main Authors: Farkas, D., Rodriguez, P.L.
• Format: Journal Article
• Language: English
• Published: Seoul Elsevier B.V 01.04.1994; Oxford Pergamon Press; New York, NY
• Subjects: 360102 - Metals & Alloys- Structure & Phase Studies; Applied sciences; BCC LATTICES; CALCULATION METHODS; Condensed matter: structure, mechanical and thermal properties; CRYSTAL DEFECTS; CRYSTAL LATTICES; CRYSTAL STRUCTURE; CUBIC LATTICES; DATA; Defects and impurities in crystals; microstructure; DISLOCATIONS; ELEMENTS; Exact sciences and technology; INFORMATION; IRON; LINE DEFECTS; Linear defects: dislocations, disclinations; MATERIALS SCIENCE; METALS; Metals. Metallurgy; NUMERICAL DATA; Physics; SCREW DISLOCATIONS; Structure of solids and liquids; crystallography; THEORETICAL DATA; TRANSITION ELEMENTS; Interatomic potential; Crystal defects; BCC lattices; Simulation; Dislocation core; Transition elements; Embedded atom method; Iron; Defect structure; Screw dislocations
• ISSN: 0956-716X
• DOI: 10.1016/0956-716X(94)90416-2

The relaxed atomistic structure of dislocation cores in body centered cubic metals was investigated many years ago, using pair potentials. These studies are now classic and have been the basis for understanding mechanical behavior of these materials. They constitute the classic example of the importance of non-elastic core effect for the dislocations responsible for deformation, as described in several reviews written on the subject. Volume-dependent interatomic potentials were introduced in 1984. Despite the importance of the results obtained with pair potentials, no calculation of dislocation cores in pure bcc metals using volume-dependent interatomic potentials has yet been performed. The purpose of the present investigation is to compute the structures of 1/2[111] screw dislocation cores Fe. The objective is to compare these results with the structures obtained with pair potentials. The computation of Peierls stresses with pair potentials usually gives an overestimate of the actual Peierls stress. In the present work, they also use an improved boundary condition technique for the simulation of the dislocation cores can give more accurate Peierls stresses using manageable atomic block sizes. They also use a more recent graphical method for the representation of the core structures to obtain the information on the core structures and their relationship to the various crystallographic planes in the material and to analyze the shape of core in relation with the possible glide planes of the dislocation.