Influence of dislocations on the spatial variation of microstructure in martensites

0355091 - ÚFM 2011 RIV CH eng J - Journal Article
Gröger, Roman - Lookman, T.
Influence of dislocations on the spatial variation of microstructure in martensites.
Key Engineering Materials. Roč. 465, - (2011), s. 77-80. ISSN 1013-9826.
[Materials Structure & Micromechanics of Fracture. Brno, 28.6.2010-30.6.2010]
Institutional research plan: CEZ:AV0Z20410507
Keywords : mean-field * dislocation * plasticity * Landau theory * incompatibility
Subject RIV: BM - Solid Matter Physics ; Magnetism

Kröner's continuum theory of dislocations views each dislocation as a source of incompatibility of strains. We show that this concept can be employed efficiently in the Landau free energy functional to develop a mean-field mesoscopic model of materials with dislocations. The order parameters that represent the distortion of the parent phase are written in terms of elastic strains which are themselves coupled by incompatibility constraints. Since the “strength” of the incompatibility depends on the local density of dislocations, the presence of dislocations affects the evolution of the microstructure and vice versa. An advantage of this formulation is that long-range anisotropic interactions between dislocations appear naturally in the formulation of the free energy. This novel field-theoretical approach helps to bridge the gap in studying the behavior of materials at the length and time scales that are not attainable by atomistic or macroscopic models.
Permanent Link: http://hdl.handle.net/11104/0193936