物理化学学报 >> 2012, Vol. 28 >> Issue (09): 2037-2043.doi: 10.3866/PKU.WHXB201206131

热力学,动力学和结构化学 上一篇    下一篇

Zn-Mg合金的结构分析和Zn-Mg扩散体系的物相分布

高帅, 吴永全, 沈通, 张宁, 赖莉珊   

  1. 上海大学, 上海市现代冶金及材料制备重点实验室, 上海200072
  • 收稿日期:2012-03-22 修回日期:2012-06-13 发布日期:2012-08-02
  • 通讯作者: 吴永全 E-mail:yqwu@staff.shu.edu.cn
  • 基金资助:

    国家自然科学基金(51174131, 50974083), 国家自然科学基金和上海宝钢集团公司联合资助项目(50774112), 上海市青年科技启明星计划(07QA14021), 长江学者和创新团队发展计划(IRT0739)及上海市教育委员会科研创新项目(09YZ24)资助

Analysis of Zn-Mg Alloy Structure and Phases Distribution of Zn-Mg Diffusion System

GAO Shuai, WU Yong-Quan, SHEN Tong, ZHANG Ning, LAI Li-Shan   

  1. Shanghai Key Laboratory of Modern Metallurgy & Materials Processing, Shanghai University, Shanghai 200072, P. R. China
  • Received:2012-03-22 Revised:2012-06-13 Published:2012-08-02
  • Contact: WU Yong-Quan E-mail:yqwu@staff.shu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51174131, 50974083), Joint Funds of National Natural Science Foundation of China-Shanghai Baosteel Corporation, China (50774112), Shanghai Rising-Star Program, China (07QA14021), Program for Changjiang Scholars and Innovative Research Team in University, China (IRT0739), and Innovation Program of Shanghai Municipal Education Commission, China (09YZ24).

摘要:

分子动力学(MD)模拟常采用径向分布函数(RDF)、Honeycutt-Anderson (HA)键型指数法、原子团类型指数法(CTIM)表征物相的微观结构. 本文依据CTIM 理论, 对CTIM 进一步发展, 使CTIM 不仅能够表征bcc\fcc\hcp\非晶体, 也能表征其它晶系的晶体结构. 本文采用CTIM 完成Zn-Mg 合金标准晶体的结构表征和Zn-Mg扩散体系物相分布的分析. 结果表明: 合金组元的CTIM指数不仅反映了Mg21Zn25、MgZn2、Mg2Zn11晶体结构的差异, 也说明了Mg4Zn7、MgZn2晶体结构十分相近. Zn-Mg扩散体系两步法模拟后, 体系两端交替分布着hcp 与fcc 结构; 体系中部形成大量的非晶体; Zn原子端交替分布着hcp 与fcc 结构的界面区域主要是Zn12-C类原子.

关键词: 原子团类型指数法, Zn-Mg合金, 晶体结构, 物相分布, 两步法模拟

Abstract:

Molecular dynamics (MD) simulations usually analyze the structure of a phase by radial distribution function (RDF), the Honeycutt-Anderson (HA) bond pair analysis, and the cluster-type index method (CTIM). In this paper, we improve CTIM to allow the characterization of more kinds of crystal structure besides bcc\fcc\hcp\non-crystal based on the theory of CTIM. The crystal structures of Zn-Mg alloys have been characterized and the phase distribution of the Zn-Mg diffusion system has been analyzed by CTIM. The results show that the CTIM integers can reveal differences between the Mg21Zn25, MgZn2, and Mg2Zn11 structures, and similarities between the Mg4Zn7 and MgZn2 structures. Using a two-step simulation on the Zn-Mg diffusion system, fcc and hcp crystals occur at both extremes of the system and there are many non-crystal phases in the middle of the system. In addition, our results show that the interface structure of fcc and hcp crystals on the Zn side is mainly Zn12-C.

Key words: Cluster-type index method, Zn-Mg alloy, Crystal structure, Phases distribution, Two-step simulation

MSC2000: 

  • O641