Simulation study of effects of cooling rate on evolution of micro-cluster structures during solidification of liquid Pb

摘要: A tracing simulation has been performed for the solidification of liquid Pb at six different cooling rates by molecular dynamics method. The pair distribution function g ( r ) curves, bond-type index method Honeycutt-Andersen(HA), cluster-type and average coordination numbers have used to analyze evolution micro-cluster structures during processes. results show that there is a critical rate (in range 1×10 13 5×10 12 K·s -1 forming amorphous or crystal structure. When higher than rate, are formed mainly with 1551,1541 1431 bond-types. lower 1441 1661 bond-types bcc basic cluster (14 6 0 8 0) firstly formed, keep stable period time, then rapidly transform partial crystalline structure 1421 1422 bond-types, fcc (12 hcp basics 6) coexisting in certain proportion . At same it found obvious effects on relative clusters clusters, smaller is, bigger cluster, system tends form highly perfect