Characterizing short-range vs. long-range spatial correlations in dislocation distributions

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• 作者：Juliette Chevy ; Claude Fressengeas ; Mikhail Lebyodkin ; Vincent Taupin ; Pierre Bastie ; Paul Duval
• 关键词：Dislocation dynamics ; Self-organization ; Spatial correlation ; Hard X-ray diffraction
• 刊名：Acta Materialia
• 出版年：2010
• 出版时间：March 2010
• 年：2010
• 卷：58
• 期：5
• 页码：1837-1849
• 全文大小：1017 K

文摘

Hard X-ray diffraction experiments have provided evidence of a strongly heterogeneous distribution of dislocation densities along the axis of cylindrical ice single crystals oriented for basal slip in torsion creep. The dislocation arrangements showed a complex scale-invariant character, which was analyzed by means of statistical and multifractal techniques. A trend to decreasing autocorrelation of the dislocation distribution was observed as deformation proceeds. At low strain levels, long-range spatial correlations control the distribution, but short-range correlations in relation with cross-slip progressively prevail when strain increases. This trend was reproduced by a model based on field dislocation dynamics, a theory accounting for both long-range elastic interactions and short-range interactions through transport of dislocation densities.