首 页
滚动信息 更多 >>
英文刊《npj Computational Materials(计算材料学... (2017-05-15)
开放的数据库 (2015-12-17)
上海硅酸盐所与Nature出版集团联合创办的中国首本n... (2015-11-27)
Nature Publishing Group and Shanghai Institute ... (2015-09-24)
快捷服务
最新文章 研究综述
过刊浏览 作者须知
期刊编辑 审稿须知
相关链接
· 在线投稿
会议信息
友情链接
  中国科学院上海硅酸盐研究所
  无机材料学报
  OQMD数据库
近期文章
Faceted interfaces: a key feature to quantitative understanding of transformation morphology (面界面:对变换形态定量理解的一个关键特征)
发布时间:2016-10-08

Faceted interfaces: a key feature to quantitative understanding of transformation morphology (面界面:对变换形态定量理解的一个关键特征)

摘要:面界面是固态相变时出现的许多微观结构形态中一个典型的重要特征。对面形态的解释、预测和模拟目前仍面临挑战,对两相间非理性取向关系(ORs)和非理性界面取向(IOs)都作为首选的系统来说尤为如此。就结构奇点来说,本研究提出了一个集成框架,可能对所有候选面界面都适用。从匹配的图案、位错结构和/或台阶结构中可以确定结构奇点。所得奇异界面存在离散的IOs,可以低指数g(理性取向)和/Δg(可以是理性也可以是非理性取向)加以描述。现有各种模型依据其针对OR IO所确定的结果进行分组,然后各模型间的关联可在集成框架中得以清楚描述。在主要的奇异界面中尽可能地消除缺陷类型,往往会对OR施加核心约束。非理性IO通常是在某个方向上位错消除的结果,如O-line界面。本文还就采用二维和三维模型对O-line界面定量测定的分析方法作了评述,而且还详细举例说明了非理性界面的计算方法。对fcc/bcc合金中界面能量所作的原子计算发现,所得出的平衡剖面结果与对该合金的观察结果有很好的一致性,从而验证了结构奇点和局部能量极小值之间的关系。 

Abstract: Faceted interfaces are a typical key feature of the morphology of many microstructures generated from solid-state phase transformations. Interpretation, prediction and simulation of this faceted morphology remain a challenge, especially for systems where irrational orientation relationships (ORs) between two phases and irrational interface orientations (IOs) are preferred. In terms of structural singularities, this work suggests an integrated framework, which possibly encompasses all candidates of faceted interfaces. The structural singularities are identified from a matching pattern, a dislocation structure and/or a ledge structure. The resultant singular interfaces have discrete IOs, described with low-index g’s (rational orientations) and/or Δg’s (either rational or irrational orientations). Various existing models are grouped according to their determined results regarding the OR and IO, and the links between the models are clarified in the integrated framework. Elimination of defect types as far as possible in a dominant singular interface often exerts a central restriction on the OR. An irrational IO is usually due to the elimination of dislocations in one direction, i.e., an O-line interface. Analytical methods using both three-dimensional and two-dimensional models for quantitative determinations of O-line interfaces are reviewed, and a detailed example showing the calculation for an irrational interface is given. The association between structural singularities and local energy minima is verified by atomistic calculations of interfacial energies in fcc/bcc alloys where it is found that the calculated equilibrium cross-sections are in a good agreement with observations from selected alloys. 

 
【打印本页】【关闭本页】
版权所有 © 中国科学院上海硅酸盐研究所
地址:上海市长宁区定西路1295号 邮政编码:200050