Ni50Zr50合金凝固过程中亚稳B2相的出现：静电悬浮与分子动力学模拟研究

Appearance of metastable B2 phase during solidification of Ni50Zr50 alloy: electrostatic levitation and molecular dynamics simulation studies.

作者信息

Quirinale D G, Rustan G E, Wilson S R, Kramer M J, Goldman A I, Mendelev M I

机构信息

Division of Materials Sciences and Engineering, Ames Laboratory, Ames, IA 50011, USA. Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA.

出版信息

J Phys Condens Matter. 2015 Mar 4;27(8):085004. doi: 10.1088/0953-8984/27/8/085004. Epub 2015 Feb 4.

DOI:10.1088/0953-8984/27/8/085004

PMID:25650946

Abstract

High-energy x-ray diffraction measurements of undercooled, electrostatically levitated Ni50Zr50 liquid droplets were performed. The observed solidification pathway proceeded through the nucleation and growth of the metastable B2 phase, which persisted for several seconds before the rapid appearance of the stable B33 phase. This sequence is shown to be consistent with predictions from classical nucleation theory using data obtained from molecular dynamics (MD) simulations. A plausible mechanism for the B2-B33 transformation is proposed and investigated through further MD simulations.

摘要

对过冷的、静电悬浮的Ni50Zr50液滴进行了高能X射线衍射测量。观察到的凝固过程通过亚稳B2相的形核和生长进行，该相持续数秒后稳定的B33相迅速出现。利用从分子动力学（MD）模拟获得的数据，证明该序列与经典成核理论的预测一致。通过进一步的MD模拟，提出并研究了B2 - B33转变的一种可能机制。