A taxonomy of grain boundary migration mechanisms via displacement texture characterization
Autor: | Brandon Runnels, Elizabeth A. Holm, Ian Chesser |
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Jazyk: | angličtina |
Rok vydání: | 2021 |
Předmět: |
Coupling
Work (thermodynamics) Condensed Matter - Materials Science Materials science Polymers and Plastics Shuffling Texture (cosmology) Metals and Alloys Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences 02 engineering and technology Computational Physics (physics.comp-ph) 021001 nanoscience & nanotechnology 01 natural sciences Displacement (vector) Electronic Optical and Magnetic Materials Characterization (materials science) Shear (sheet metal) 0103 physical sciences Ceramics and Composites Grain boundary Statistical physics 010306 general physics 0210 nano-technology Physics - Computational Physics |
Popis: | Atomistic simulations provide the most detailed picture of grain boundary (GB) migration currently available. Nevertheless, extracting unit mechanisms from atomistic simulation data is difficult because of the zoo of competing, geometrically complex 3D atomic rearrangement processes. In this work, we introduce the displacement texture characterization framework for analyzing atomic rearrangement events during GB migration, combining ideas from slip vector analysis, bicrystallography and optimal transportation. Two types of decompositions of displacement data are described: the shear-shuffle and min-shuffle decomposition. The former is used to extract shuffling patterns from shear coupled migration trajectories and the latter is used to analyze temperature dependent shuffling mechanisms. As an application of the displacement texture framework, we characterize the GB geometry dependence of shuffling mechanisms for a crystallographically diverse set of mobile GBs in FCC Ni bicrystals. Two scientific contributions from this analysis include 1) an explanation of the boundary plane dependence of shuffling patterns via metastable GB geometry and 2) a taxonomy of multimodal constrained GB migration mechanisms which may include multiple competing shuffling patterns, period doubling effects, distinct sliding and shear coupling events, and GB self diffusion. |
Databáze: | OpenAIRE |
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