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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.

在原子水平上，金属材料中的应变局部化受位错的传播、位错附近的外来原子的运动、位错之间的相互作用以及位错与不均匀性（固溶原子、析出物和晶界）的相互作用控制。在宏观层面上，析出物对铝镁合金力学性能的影响可以通过拉伸试验中不均匀的变形行为的形式被注意到。这也被称为Portevin-Le Chatelier（PLC）效应。尽管对PLC效应有大量的实验结果和先进的模拟方法，但原子尺度上PLC效应的基本现象仍然没有被完全理解。我们打算在拟议项目的框架内系统地缩小这一差距。借助分子动力学 (MD) 模拟，我们将在纳米级水平上研究有助于铝镁合金材料硬化的过程。临界解析剪切应力 (CRSS) 源于各种沉淀物类型和尺寸，并通过 MD 进行计算，以研究它们对材料硬化的影响。应力和应变控制变形都将被模拟，结果将相互验证以及文献值验证。