Lu Xuefeng, Yang Panfeng, Luo Jianhua, Ren Junqiang, Xue Hongtao, Ding Yutian
State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metal, Department of Materials Science and Engineering, Lanzhou University of Technology Lanzhou 730050 PR China
RSC Adv. 2019 Aug 19;9(44):25817-25828. doi: 10.1039/c9ra04294f. eCollection 2019 Aug 13.
In this present contribution, tensile mechanical properties of Ni-Co alloy nanowires with Co content from 0 to 20% were studied by molecular dynamics. The simulation results show the alloy nanowire with the Co content of 5% has the highest yield value of 9.72 GPa. In addition, more Frank dislocations were generated during the loading process to improve the performance of the alloy nanowire. The Young's modulus increases little by little from 105.68 to 179.78 GPa with the increase of Co content. Secondly, with the increase of temperature, the yield strength gradually decreases to 2.13 GPa. Young's modulus tends to decrease linearly from 170.7 GPa to 48.21 GPa. At the temperatures of 500 K and 700 K, it is easier to form Frank dislocation and Hirth dislocation, respectively, in the loading process. The peak value of the radial distribution function decreases and the number of peaks decreases, indicating the disappearance of the ordered structure. Finally, after the introduction of the surface and inner void, the yield strength of the nanowire drops about to 8.97 and 6.6 GPa, respectively, and the yield strains drop to 0.056 and 0.043. In the case of the existence of internal void, perfect dislocation and Hirth dislocation can be observed in the structure.
在本论文中，通过分子动力学研究了钴含量从0到20%的镍钴合金纳米线的拉伸力学性能。模拟结果表明，钴含量为5%的合金纳米线具有最高屈服值9.72 GPa。此外，在加载过程中产生了更多的弗兰克位错以改善合金纳米线的性能。随着钴含量的增加，杨氏模量从105.68 GPa逐渐增加到179.78 GPa。其次，随着温度升高，屈服强度逐渐降低至2.13 GPa。杨氏模量倾向于从170.7 GPa线性降低至48.21 GPa。在500 K和700 K温度下，加载过程中分别更容易形成弗兰克位错和赫斯位错。径向分布函数的峰值降低且峰数减少，表明有序结构消失。最后，引入表面和内部孔洞后，纳米线的屈服强度分别降至约8.97 GPa和6.6 GPa，屈服应变降至0.056和0.043。在存在内部孔洞的情况下，结构中可观察到完美位错和赫斯位错。
