Size distributions and magic number characteristics of cluster configurations formed during solidification processes of liquid metal Al  

作　　者：LIU Rangsu1, LIU Fengxiang1, DONG Kejun1, ZHENG Caixing1, LIU Hairong2, PENG Ping2 & LI Jiyong3 1. Department of Physics, Hunan University, Changsha 410082, China 2. Department of Material Science and Engineering, Hunan University, Changsha 410082, China 3. Department of Chemistry, Hunan University, Changsha 410082, China 

出　　处：《Science China(Technological Sciences)》2006年第2期172-187,共16页中国科学（技术科学英文版）

基　　金：This work was supported by the National Natural Science Foundation of China (Grant No. 50271026).

摘　　要：A molecular dynamics simulation study has been performed for a large systemconsisting of 100000 liquid metal Al atoms to investigate the formation and magic numbercharacteristics of the cluster configurations formed during the rapid solidification processes. Thecluster-type index method (CTIM) has been adopted to describe various types of clusterconfigurations. The results indicate that the icosahedral clusters (12 0 12 0) and theircombinations play the most important role in the rnicrostructure transitions during solidificationprocesses; for the cluster configurations of different levels formed by various combinations withdiffering numbers of basic clusters, their size distributions possess obvious magic number sequencewhich is in turn as 13(13), 19(21), 26-28(27), 32-33(32), 39-40, 43-44, 48..., (those in bracket arethe corresponding value in liquid state); the magic numbers correspond to the peak value positionsof the cluster numbers for corresponding level formed with various combinations by 1, 2, 3, 4, 5, 6,7, ...basic clusters, respectively. This magic number sequence is in good agreement with theexperimental results obtained by Harris et al. At the same time, this simulation study also gives ascientific and reasonable explanation to these experimental results.

关 键 词：liquid metal  SOLIDIFICATION processes  CLUSTER configuration  MAGIC numbers  computer simulation. 

分 类 号：TG292[金属学及工艺—铸造]