Finding Critical Nuclei in Phase Transformations by Shrinking Dimer Dynamics and its Variants

作     者：Lei Zhang Jingyan Zhang Qiang Du 

作者机构：Beijing International Center for Mathematical ResearchPeking UniversityBeijing 100871China. Department of MathematicsPennsylvania State UniversityPA 16802USA. Beijing Computational Science Research CenterBeijing100084China. 

出 版 物：《Communications in Computational Physics》 (计算物理通讯（英文）)

年 卷 期：2014年第16卷第8期

页      面：781-798页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：NSF-DMS 1016073 and 1318586 and the Recruitment Program of Global Youth Experts in China 

主　　题：Critical nucleus phase field models saddle point shrinking dimer dynamics heterogeneous nucleation precipitate nucleation phase transformation 

摘      要：We investigate the critical nuclei morphology in phase transformation by combining two effective ingredients,with the first being the phase field modeling of the relevant energetics which has been a popular approach for phase transitions and the second being shrinking dimer dynamics and its variants for computing saddle points and transition *** particular,the newly formulated generalized shrinking dimer dynamics is proposed by adopting the Cahn-Hilliard dynamics for the generalized gradient *** illustrations,a couple of typical cases are considered,including a generic system modeling heterogeneous nucleation and a specific material system modeling the precipitate nucleation in FeCr *** the standard shrinking dimer dynamics can be applied to study the non-conserved case of generic heterogeneous nucleation directly,the generalized shrinking dimer dynamics is efficient to compute precipitate nucleation in FeCr alloys due to the conservation of *** simulations are provided to demonstrate both the complex morphology associated with nucleation events and the effectiveness of generalized shrinking dimer dynamics based on phase field models.