基于分子动力学模拟下CuZr金属玻璃的局域连接度对拉伸性能的影响

二十面体连接网络是由二十面体相互连接而形成的中程有序结构。利用分子动力学模拟方法研究了CuZr金属玻璃在拉伸过程中的二十面体连接网络的演变。结果表明,二十面体连接网络会因为变形而断裂,从而出现孤立的二十面体,或是转变成其他团簇。高的米瑟斯应力和屈服时更少的连接度数量百分比可以解释Cu含量低的样品中的较低强度和良好塑性。此外,在Cu含量高的样品中,低连接度在变形后更倾向于向高连接度转变,让样品在变形后仍保持着较高的连接度,呈现为强度高,塑性低的力学性能。

Effect of local connectivity on tensile properties of CuZr metallic glasses under molecular dynamics simulations

Interpenetrating connection of icosahedral network (ICOIN) is a medium-range ordered (MRO) structure formed by connecting icosahedra. The evolution of MRO structures in metallic glasses (MG) under tensile deformation was studied using molecular dynamics simulations. The results show that ICOIN of the sample broke due to the tension, a few of them became disconnected and turned into isolated icosahedral clusters or transformed into other types of clusters. A smaller quantity fraction of connectivity at yielding and higher Mises stresses could be a good match for the lower strength and good plasticity of the sample with low Cu content. In addition, in the sample with high Cu content, the icosahedra with low connectivity were more inclined to transform to high connectivity, causing the sample to remain higher connectivity after deformation and exhibiting high yield strength and low plasticity.