复杂合金相T⁃Al⁃Mn⁃Pd中位错交互作用及其特殊构型的电子显微学研究

Metadislocation interaction and atomic⁃scale configuration in deformed complex metallic alloy T⁃Al⁃Mn⁃Pd

复杂合金相中新型位错(metadislocation)的发现为理解大晶格参数复杂合金材料的塑性变形行为提供了重要基础。本文概述了复杂合金相T⁃Al⁃Mn⁃Pd高温变形显微结构中此类位错交互作用及其特殊构型的最新进展,并针对不同缺陷构型与变形机制的关联进行了综合讨论。原子尺度透射电镜表征发现复杂合金相中具有相反方向伯氏矢量的近邻位错会通过两条共用的相子链连接产生交互作用,从而构成一种特殊的位错偶。同时,变形结构中也观察到反相子及其变体缺陷,基于相关最新进展及反相子缺陷构建了复杂合金相位错形成的拼砌模型,提出一种基于反相子变体结构的位错偶形成机制。

The study of metadislocations in complex metallic alloys provides an important basis for understanding the plastic deformation in complex solids with large lattice parameters.This paper discusses the recent progress of dislocation interaction and related configuration in the high⁃temperature deformation microstructure of complex metallic alloy T⁃Al⁃Mn⁃Pd and the correlation between different defect configurations and deformation mechanisms.Atomic⁃scale transmission electron microscopy characterizations show that adjacent metadislocations with opposite signs interact through two shared chains of phason defects and form dipolar configurations.Anti⁃phason defects and their structural variants are also observed.Tiling models for metadislocation formation based on anti⁃phasons and recent related progress are constructed.A possible mechanism for dipole formation based on an anti⁃phason variant is proposed.