arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2003.09973cond-mat.mtrl-sci
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纳米尺度下铝铜合金力学性能的数值研究

Numerical Investigation of Mechanical Properties of Aluminum-Copper Alloys at Nanoscale

Satyajit Mojumder, Md Shajedul Hoque Thakur, Mahmudul Islam, Monon Mahboob, Mohammad Motalab

摘要:

纳米压痕是一种强大的工具,能够提供在纳米尺度上的材料弹性和塑性响应的基本见解。纳米尺度的合金特别有趣,因为原子研究揭示的局部异质性和变形机制为理解硬化机制提供了更好的方法,以构建更坚固的材料。本文采用原子模拟的方法研究了Al-Cu合金中的纳米压痕,通过位错驱动机制研究了加载方向、Cu合金化比例对压痕的影响。此外,一个低保真度的有限元(FE)模型已被开发用于纳米压痕模拟,其中纳米级材料的属性是从原子模拟。材料性能,如硬度和折合模量,计算从FE和MD模拟,然后比较。考虑到这两种数值方法之间的根本差异,从本研究中得到的有限元结果符合相当从MD模拟。这为在不需要高保真度结果的情况下使用FE以减少的模拟时间和成本找到合金的材料特性铺平了道路。计算结果包括载荷-位移分析、位错密度、位错环形核与扩展、应力分布和表面压痕。本文所采用的将原子数据纳入有限元模拟的技术可以进一步扩展,以寻找其他复杂合金材料的力学和断裂性能。

英文摘要:

Nanoindentation is a powerful tool capable of providing fundamental insights of material elastic and plastic response at the nanoscale. Alloys at nanoscale are particularly interesting as the local heterogeneity and deformation mechanism revealed by atomistic study offers a better way to understand hardening mechanism to build a stronger material. In this work, nanoindentation in Al-Cu alloys are studied using atomistic simulations to investigate the effects of loading direction, alloying percentages of Cu via dislocation-driven mechanisms. Also, a low-fidelity finite element (FE) model has been developed for nanoindentation simulations where nanoscale materials properties are used from atomistic simulations. Material properties, such as hardness and reduced modulus, are computed from both the FE and MD simulations and then compared. Considering the fundamental difference between these two numerical approaches, the FE results obtained from the present study conform fairly with those from MD simulations. This paves a way into finding material properties of alloys with reduced simulation time and cost by using FE where high-fidelity results are not required. The results have been presented as load-displacement analysis, dislocation density, dislocation loops nucleation and propagation, von-Mises stress distribution and surface imprints. The techniques adopted in this paper to incorporate atomistic data into FE simulations can be further extended for finding other mechanical and fracture properties for complex alloy materials.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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