Glass-formation and atomic structures of Cux(Zr0.22Hf0.78)1−x and (Cu0.61Hf0.39)1−xZrx alloys investigated by Monte Carlo simulation

Abstract

Based on a realistic Cu–Zr–Hf n-body potential, Monte Carlo simulations were conducted to investigate effect of constituent elements on the forming ability, energetic state and atomic configuration of metallic glasses in two pseudo-binary systems, i.e. the Cux(Zr0.22Hf0.78)1−x and (Cu0.61Hf0.39)1−xZrx (0<x<1). The simulation results first determined the glass-forming ranges of each system, within which amorphous phase was energetically favored compared to its crystalline counterpart and the maximum driving forces for crystalline-to-amorphous transition of the two systems locating almost at the same composition. Voronoi tessellation analysis revealed that the atomic structures of the two systems were obviously affected by the concentration of Cu and Zr, respectively, and the coordination number distribution could be a clear indication pinpointing the respective glass-forming ranges. Moreover, the calculated microchemical inhomogeneity showed a negative tendency upon amorphization, suggesting that there exhibits short-range chemical ordering in the two pseudo-systems and in the amorphous phase, an atom would prefer to have the dissimilar atoms to be its neighbors.