Glass forming abilities of binary Cu100-x Zrx (34, 35.5, and 38.2 at. %) metallic glasses: A LAMMPS study

Using large-scale atomic/molecular massively parallel simulator (LAMMPS), we have studied the liquid behaviors of Cu61.8 Zr38.2, Cu64.5 Zr35.5, and Cu66 Zr34 amorphous alloys including their pair distribution functions, distributions of Voronoi clusters with different coordination numbers, and mean square displacements of Cu and Zr atoms. Compared to Cu61.8 Zr38.2 and Cu66 Zr34, we found high concentrations of distorted icosahedra with indices of 〈 0,2,8,2 〉 and 〈 0,4,4,4 〉, high numbers of Cu-centered Cu8 Zr5 and Cu9 Zr4 clusters, and reduced atomic diffusivity of Cu and Zr atoms in molten Cu64.5 Zr35.5 alloy. These effects would benefit glass formation in Cu64.5 Zr35.5 alloy. Meanwhile, from the viewpoints of local cluster structure, the majority of the glue atoms are Cu atoms in Cu64.5 Zr35.5 amorphous alloy, which leads to denser packing and better glass forming ability.