Nucleation and Growth of Solid-State Transformations

固态转变的成核和生长

• 批准号: 9806749
• 负责人: Gregory Olson
• 金额: $ 43.5万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9806749&HistoricalAwards=false
• 关键词: Nucleation; Growth; Solid; State; Transformations

9806749OlsonThis research program is directed toward principles of first-order solid-state phase transformations using the prototypical case of martensitic reactions. Theory and experiment address multiscale microstructural evolution, exploiting nonlinear nonlocal models to bridge length scales. Landau-Ginsburg models are incorporated within an Element-Free Galerkin (EFG) method to compute 3D structures of martensitic embryos forming at dislocation defects in steels, investigating nucleation precursors and coherency transitions. For realistic treatment of technologically important systems including steels and shape memory alloys, FP-LMTO total energy electronic calculations address the nonlinear energetics of martensitic lattice deformations for incorporation in the continuum calculations. Nonlocal plasticity models are applied to the problem of martensitic growth in plastic media, as the basis of modeling morphological transitions. Quantitative stereological measurements in thermoelastic and non-thermoelastic systems define nucleation site potency distributions and the evolution of particle volume. These are combined in a comprehensive kinetic model incorporating morphological transitions. The relevance of martensite theory to molecular level protein displacive transformations is explored in biological systems of current interest.%%%This research group is the leading activity in the United States in designing metal alloys for application in industry. The approach is fundamental and relies on both experimental measurements and theory.***

[8067449] olson这个研究项目是利用马氏体反应的原型案例来研究一阶固态相变的原理。理论和实验解决多尺度微观结构的演变，利用非线性非局部模型桥梁长度尺度。Landau-Ginsburg模型被纳入到一种无元素伽辽金（EFG）方法中，用于计算在钢的位错缺陷处形成的马氏体胚胎的三维结构，研究成核前体和相干转变。对于包括钢和形状记忆合金在内的技术重要系统的实际处理，FP-LMTO总能量电子计算解决了马氏体晶格变形的非线性能量学，并将其纳入连续介质计算中。非局部塑性模型应用于马氏体在塑性介质中的生长问题，作为模拟形态转变的基础。热弹性和非热弹性体系的定量立体学测量定义了成核位势分布和粒子体积的演化。这些都结合在一个综合的动力学模型结合形态转变。马氏体理论与分子水平蛋白质位移转化的相关性在当前感兴趣的生物系统中进行了探讨。这个研究小组在设计用于工业的金属合金方面处于美国的领先地位。该方法是基本的，依赖于实验测量和理论