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Molecular dynamics simulations on the influence of precipitates on the strain localization in aged Al-Mg alloys

析出物对时效铝镁合金应变局部化影响的分子动力学模拟

基本信息

批准号：
269506753
负责人：
Professor Dr. Siegfried Schmauder
金额：
--
依托单位：
Institut für Materialprüfung, Werkstoffkunde und Festigkeitslehre (IMWF)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/269506753?language=en
关键词：
Molecular dynamics simulations influence precipitates

项目摘要

The strain localization in metallic materials is, at the atomic level, governed by the propagation of dislocations, the movement of foreign atoms in the vicinity of dislocations, the interaction of dislocations with each other and by the interaction of dislocations with inhomogeneities (solid soluted atoms, precipitates and grain boundaries). At the macroscopic level, the effect of precipitates on the mechanical properties of Al-Mg alloys can be noticed in the form of an uneven deformation behavior during tensile tests. This is also known as the Portevin - Le Chatelier (PLC) effect.Despite extensive experimental results to the PLC effect and advanced simulation methods, the basic phenomena of the PLC effect at the atomistic scale are still not fully understood. It is our intention to systematically close this gap within the frame of the proposed project. Processes contributing to the material hardening in Al-Mg alloys will be investigated at the nanoscale level with the help of molecular dynamics (MD) simulations.Critical resolved shear stresses (CRSS), originating from various precipitate types and sizes and calculated by MD in order to investigate their influence onto the material hardening. Both stress- and strain controlled deformations will be simulated, the results will be validated by each other as well as by literature values.

金属材料中的应变局部化在原子水平上由位错的传播、位错附近的外来原子的运动、位错彼此的相互作用以及位错与不均匀性（固溶原子、沉淀物和晶界）的相互作用来控制。在宏观水平上，析出物对Al-Mg合金力学性能的影响可以以拉伸试验期间不均匀变形行为的形式被注意到。这也被称为波特万-勒夏特列（PLC）效应。尽管对PLC效应有广泛的实验结果和先进的模拟方法，但在原子尺度上PLC效应的基本现象仍然没有完全理解。我们打算在拟议项目的框架内系统地弥合这一差距。本文采用分子动力学（MD）模拟方法，在纳米尺度上研究了Al-Mg合金中的材料硬化过程，计算了不同析出相类型和尺寸的临界分辨剪切应力（CRSS），研究了其对材料硬化的影响。应力和应变控制的变形将被模拟，结果将相互验证，以及文献值。