Cu_(80)Zr_(20)金属玻璃结构不均匀性的研究

Study on Structural Heterogeneity of Cu_(80)Zr_(20)Metallic Glass

采用经典分子动力学模拟方法研究了Cu_(80)Zr_(20)合金体系在快速淬火过程的微观结构变化.发现了合金中存在着以二十面体为骨架的不均匀结构,同时也存在着以势能较低原子的为骨架的不均匀结构.计算了二十面体在能量最低结构中所占的比例,发现在1200K以上时,二十面体在能量最低结构中比例仅在10%以下,此比例随温度的降低而上升,在100K时比例为35.6%.结果表明体系中存在着能量不均匀性和结构不均匀性,但二者并不一致,不是同一种不均匀性.

The microstructure of Cu_(80)Zr_(20)alloy during quenching is studied by classical molecular dynamics simulation.It is found that there are heterogeneity structures with icosahedron as the skeleton in the alloy,and there are also heterogeneity structures with lower potential energy atoms as the skeleton.The proportion of icosahedron in the lowest energy structure is calculated.The proportion of icosahedron in the lowest energy structure is only less than 10%at above 1200 K,which increases with decreasing temperature,and was 35.6%at 100 K.The results show that there are energy heterogeneity and structure heterogeneity in the system,but they are not the same kind of heterogeneity.