Nanoindentation response of monocrystalline copper under various tensile pre-deformations via molecular dynamic simulations
Nanoindentation response of monocrystalline copper under various tensile pre-deformations via molecular dynamic simulations
复制标题
通过分子动力学模拟单晶铜在各种预应力变形下的纳米压痕响应
DOI：
10.1177/1687814018816874
复制
发表时间：
2018-12-07
影响因子：
2.1
通讯作者：
Ma, Zhichao
中科院分区：
文献类型：
--
作者：
Li, Lijia;Sun, Xingdong;Ma, Zhichao
材料的机械性能可以受到其施加或残留应力的正面或负面影响。在本文中，采用了一系列分子动力学模拟来研究拉伸预染色下单晶铜的纳米引起响应。将无应力条件下的纳米凹陷模拟与张力前应变值下的纳米凹陷模拟进行了比较，为1.2％，2.4％和3.6％。获得了基于各种拉伸预申请的纳米指标的硬度值和恢复率的负载置换曲线并进行了讨论。它表明，拉伸预染色会导致底物的势能较高，并且将引入较低的外部能量，以实现压痕期间相同的弹性或塑性变形。此外，还观察到并分析了凹痕过程中内部缺陷的演变。结果表明，拉伸前应变会影响压痕过程中材料的脱位成核行为。本文提出了一种特殊的分子动力学模拟方法，以通过纳米识别来表征材料在拉伸预构型下的机械性能，该特性在微观和纳米级的残留应力方面提供了有效的方法，并将有望在微观机械系统的机械机械系统的手段和结构的机械表征中使用。基于实验的进一步分析将在我们的进一步研究工作中进行。
The mechanical properties of a material can be positively or negatively affected by its applied or residual stress. In this article, a series of molecular dynamic simulations were adopted to investigate the nanoindentation response of monocrystalline copper under tensile pre-deformation. Nanoindentation simulation under stress-free condition was compared with those under pre-tension strain values of 1.2%, 2.4% and 3.6%. Load-displacement curves with hardness value and recovery rates of total work for nanoindentation based on various tensile pre-deformations were obtained and discussed. It indicated that tensile pre-deformations resulted in a higher potential energy in substrate and a lower external energy will be introduced to realize the same elastic or plastic deformation during indentation. Moreover, the evolution of interior defects during indentation was also observed and analysed. The results showed that tensile pre-strain can influence dislocation nucleation behaviour of material during indentation. This article proposed a special molecular dynamic simulation method to characterize the mechanical properties of the material under tensile pre-deformations via nanoindentation, which gives an effective approach to characterize residual stresses in micro- and nanoscale and will have promising application in mechanical characterization of Microelectro Mechanical Systems devices and structures. Further analysis based on experiments will be done in our further research work.