Evolution of local atomic structures during rapid solidification of liquid metal W

Abstract

Molecular dynamics (MD) simulations were performed to investigate the evolution of local atomic structure during rapid solidification of liquid metal W. The microstructures were characterized by means of potential energy (PE) per atom, pair distribution function and largest standard cluster analysis (LSCA). Instead of [12/555] perfect icosahedra, the [8/555 2/544 2/433] distorted icosahedra dominated in W monatomic metallic glasses (MGs). With the decrease of temperature, these clusters in metal W systems aggregated steeply into icosahedral medium-range orders (IMROs), especially in the super-cooling liquid region. Moreover, the maximal size [Formula: see text] of IMROs played a control role in the formation of W monatomic MGs rather than the number [Formula: see text]. The mean local fivefold symmetry [Formula: see text] of IMROs was demonstrated to be an effective indicator to characterize the glass transition of monatomic metal W liquids.