Molecular dynamics simulations of the effects of nanopores on mechanical behavior in the Mg2Sn system
Molecular dynamics simulations of the effects of nanopores on mechanical behavior in the Mg2Sn system
复制标题
纳米孔对 Mg2Sn 体系机械行为影响的分子动力学模拟
DOI：
10.1016/j.commatsci.2019.01.043
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发表时间：
2019-04
影响因子：
3.3
通讯作者：
Zhai Pengcheng
中科院分区：
文献类型：
--
作者：
Huang Min;Yang Xuqiu;Chen Gang;Li Guodong;Zhai Pengcheng
二元化合物Mg_2Sn由于其组成元素丰富、在工作条件下无毒性等优点，在热电能量转换方面的应用受到广泛关注。在Mg 2Sn晶体中引入纳米级孔可以显著降低晶格热导率，同时纳米孔可能会削弱Mg 2Sn商业应用中重要的机械性能。为了确定纳米孔对Mg 2Sn力学行为的影响，我们通过分子动力学（MD）模拟研究了均匀和随机分布的纳米孔块体中拉伸和剪切变形的应力响应。我们发现，纳米孔降低的力学性能，如极限应力，断裂应变和弹性模量的结晶Mg 2Sn。此外，随机分布的纳米多孔Mg 2Sn的力学性能比均匀分布的纳米多孔Mg 2Sn差。纳米孔导致极限应力和弹性模量的降低。同时，强度和刚度与孔隙率密切相关，而与孔隙半径无关。在拉伸载荷的情况下，在纳米孔附近的（0 0 1）/倾斜取向的裂纹<1 1 0>导致锯齿形断裂表面。在剪切载荷下，原子浓度、孔隙合并和剪切带是材料断裂的主要机制。研究结果为不同加载方式下纳米多孔Mg 2Sn的失效机理提供了新的视角。
Binary compound Mg2Sn has received close attention for the thermoelectric energy conversion application, due to the abundance of constituent elements and the non-toxicity in the working condition. The introduction of nano-scale pores into crystalline Mg2Sn can significantly reduce the lattice thermal conductivity, while the nanopores might weaken the mechanical properties that are important for the commercial applications of Mg2Sn. To determine the effect of nanopores on mechanical behavior of Mg2Sn, we investigate the stress responses of tensile and shear deformations in uniformly and randomly distributed nanoporous bulks by using molecular dynamics (MD) simulations. We find that nanopores reduce the mechanical properties such as ultimate stress, fracture strain and elastic modulus of crystalline Mg2Sn. Furthermore, mechanical properties of randomly distributed nanoporous Mg2Sn are poorer than those of uniformly distributed nanoporous Mg2Sn. Nanopores lead to a reduction both in ultimate stress and elastic modulus. Meanwhile, the strength and the stiffness are closed related to porosity rather than radius of pores. In the case of tensile loading, the crack of (0 0 1)/<1 1 0> tilt orientations in the vicinity of nanopores results in zigzag breakage surfaces. As for shear loading, the atomic concentration, pore coalescence and shear band explore the fracture mechanism. Our results provide new perspectives of failure mechanism of nanoporous Mg2Sn under different loading methods.
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影响因子：
5.2
作者：
Chaohai Zhang;Zhen Liu;P. Deng
通讯作者：
Chaohai Zhang;Zhen Liu;P. Deng
影响因子：
16.6
作者：
Heiranian M;Farimani AB;Aluru NR
通讯作者：
Aluru NR
Sb空位缺陷对CoSb3晶格热导率影响的分子动力学研究
影响因子：
3.3
作者：
Liu, Zi;Yang, Xuqiu;Chen, Gang;Zhai, Pengcheng
通讯作者：
Zhai, Pengcheng
影响因子：
5.3
作者：
Florence Scheyvaerts;P. Onck;C. Tekoğlu;T. Pardoen
通讯作者：
Florence Scheyvaerts;P. Onck;C. Tekoğlu;T. Pardoen
DOI：
10.1016/j.msea.2004.08.071
发表时间：
2005-01-15
影响因子：
6.4
作者：
Ivanisenko, Y;Valiev, RZ;Fecht, HJ
通讯作者：
Fecht, HJ