物理化学学报 >> 2012, Vol. 28 >> Issue (07): 1586-1592.doi: 10.3866/PKU.WHXB201205042

热力学,动力学和结构化学 上一篇    下一篇

基于液态合金短程序的混合构型熵新模型

秦敬玉   

  1. 山东大学材料液固态结构演变与加工教育部重点实验室, 济南 250061
  • 收稿日期:2012-03-31 修回日期:2012-05-04 发布日期:2012-06-07
  • 通讯作者: 秦敬玉 E-mail:qinjy@sdu.edu.cn
  • 基金资助:

    国家自然科学基金(50971082)资助项目

A New Model for the Configurational Entropy of Mixing in Liquid Alloys Based on Short-Range Order

QIN Jing-Yu   

  1. Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of Education, Shandong University, Jinan 250061, P. R. China
  • Received:2012-03-31 Revised:2012-05-04 Published:2012-06-07
  • Contact: QIN Jing-Yu E-mail:qinjy@sdu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (50971082).

摘要:

基于液态合金化学短程序与拓扑短程序发展了一个新的混合构型熵计算模型, 从这个模型可以导出用来描述等原子直径随机混合物的理想混合熵. 通过将该模型应用于一些理想的和真实的液态二元合金, 可以看到化学短程序减小了混合构型熵, 而原子尺寸差异的影响则较为复杂. 当大原子进入小原子基体时, 混合构型熵增大; 而当小原子进入大原子基体时, 混合构型熵减小. 在这些合金中, 共晶成分处并没有出现混合构型熵极大值.

关键词: 液态合金, 短程序, 混合构型熵

Abstract:

A new model has been developed to calculate the configurational entropy of mixing in liquid alloys involving consideration of chemical and topological short-range order. The entropy of mixing for an equiatomic random mixture was naturally reached by this model. The application of this model to both hypothetic and real binary liquid alloys demonstrated that the chemical short-range order always decreased the configurational entropy of mixing, whereas complicated behavior was found with the atomic size effect. The configurational entropy of mixing increased when the larger atoms entered into the matrix of the smaller atoms, whereas it decreased when the smaller atoms were mixed into the matrix of the larger atoms. The maximum of the configurational entropy of mixing was not located at the eutectic composition in these alloys.

Key words: Liquid alloy, Short-range order, Configurational entropy of mixing

MSC2000: 

  • O642