锂对铁素体拉伸力学行为影响的分子动力学研究

doi:10.7523/j.ucas.2020.0024

摘要/Abstract

摘要： 液态锂第一壁是磁约束核聚变领域的先进概念，相对于传统的固体壁材料，越来越多的实验表明液态锂壁具有独特的优势，不仅可以有效解决固体壁材料所面临的物理化学溅射、氚滞留等一系列问题，同时还可以显著提高等离子体的约束性能。然而，液态锂对大部分金属材料都具有很强的腐蚀特性，腐蚀引起的微观结构变化必然带来材料宏观力学性能的退化，对于结构材料而言，力学性能的退化将给整个装置带来安全隐患。基于此，采用分子动力学方法对单晶铁素体进行单轴拉伸模拟，分析锂原子对其塑性变形行为和屈服应力的影响。结果表明，锂原子可以显著抑制相变的发生，从而改变铁素体的塑性变形模式，同时影响屈服应力的大小以及与温度的变化关系。

关键词: 分子动力学, 单轴拉伸, 力学性能, 铁, 锂

Abstract: Liquid lithium first wall is an advanced concept in the field of magnetic confinement fusion. Compared with the traditional solid wall materials, more and more experiments have shown that liquid lithium wall has unique advantages, which can not only effectively solve a series of problems faced by solid wall materials such as sputtering and tritium retention, but also significantly improve the constraint performance of core plasma. However, liquid lithium has brought severe corrosion problems to most metal materials, and the microstructure changes caused by corrosion will inevitably lead to the degradation of the macroscopic mechanical properties of materials. For structural materials, the degradation of mechanical properties will bring safety risks to the entire device. Based on this, the uniaxial tensile simulations of single crystal alpha-iron were carried out by using molecular dynamics, and the effects of lithium atoms on the plastic deformation behavior and yield stress were analyzed in this paper. The results show that lithium atoms can significantly suppress the phase transition, change the plastic deformation mode of alpha-iron, and affect the yield stress and its relationship with temperature.

Key words: molecular dynamics, uniaxial tension, mechanical properties, iron, lithium

中图分类号:

O482.1

魏炜, 余新刚. 锂对铁素体拉伸力学行为影响的分子动力学研究[J]. 中国科学院大学学报, 2022, 39(1): 13-20.

WEI Wei, YU Xin'gang. Molecular dynamics study of the effect of lithium on the tensile mechanical behavior of alpha-iron[J]. Journal of University of Chinese Academy of Sciences, 2022, 39(1): 13-20.

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