中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 30 No. 11 November 2020 |
（1. College of Computer Science and Electronic Engineering, Hunan University, Changsha 410082, China;
2. College of Physics and Electronics, Hunan Institute of Science and Technology, Yueyang 414000, China;
3. School of Electronic Information and Electrical Engineering, Changsha University, Changsha 410022, China;
4. Centre for Infrastructure Engineering, School of Engineering, University of Western Sydney, Penrith NSW 2751, Australia;
5. College of Materials Science and Engineering, Hunan University, Changsha 410082, China）
Abstract:The phase transition of tungsten (W) under high pressures was investigated with molecular dynamics simulation. The structure was characterized in terms of the pair distribution function and the largest standard cluster analysis (LSCA). It is found that under 40-100 GPa at a cooling rate of 0.1 K/ps a pure W melt first crystallizes into the body-centred cubic (BCC) crystal, and then transfers into the hexagonal close-packed (HCP) crystal through a series of BCC-HCP coexisting states. The dynamic factors may induce intermediate stages during the liquid-solid transition and the criss-cross grain boundaries cause lots of indistinguishable intermediate states, making the first-order BCC-HCP transition appear to be continuous. Furthermore, LSCA is shown to be a parameter-free method that can effectively analyze both ordered and disordered structures. Therefore, LSCA can detect more details about the evolution of the structure in such structure transition processes with rich intermediate structures.
Key words: molecular dynamics (MD) simulation; rapid solidification; solid-solid phase transition; largest standard cluster analysis; topologically close-packed cluster
