液态Cu50Zr50合金快速凝固过程中二十面体团簇的遗传与演化

molecular dynamics (MD) simulation has been performed to investigate the heredity characteristics of icosahedral clusters during the rapid solidification of liquid Cu50Zr50 alloy. Pair distribution functions, Honeycutt-Andersen bond-type index, cluster-type index and atom tracking method have been adopted to characterize and analyze the evolution of configurations with various geometrical symmetries and chemical short-range orders. The results reveal that the number of basic (12 0 12 0) icosahedra and their distorted configurations (12 2/1431 2/1541 8/1551) significantly increases at the glassy transformation temperature Tg = 870K, and most of which are Cu-centered Cu6Zr7 clusters. No evidence indicates icosahedra in liquid Cu50Zr50 alloy can be directly transmitted to solid amorphous alloy at a cooling rate of 5K/ns. These icosahedral clusters in amorphous alloys mainly originate from the super-cooling liquid alloy, and majority depends on the direct and perfect heredity mode as well as the partial heredity mode. The double-layer icosahedrons formed by bonding the central atoms of the basic clusters (12 0 12 0), exhibit excellent partial heredity during the rapid solidification.