Materials World Networ: Collaborative Research: Theoretical, Computational and Experimental Studies of 3D Microstructural Evolution in Ultra-high Volume Fraction Coarsening Systems

材料世界网络：协作研究：超高体积分数粗化系统中 3D 微观结构演化的理论、计算和实验研究

• 批准号: 0710483
• 负责人: Long-Qing Chen
• 金额: $ 26.5万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0710483&HistoricalAwards=false
• 关键词: Materials; World; Networ; Collaborative; Research

Florida Institute of Technology and Penn State University in the US team up with Ulm University and the Technical University in Dresden, Germany, to address the fundamental problem of phase coarsening. The primary goal of this project is to understand the kinetics of phase coarsening at ultra-high ( 90%) volume fractions, which are expected to be fundamentally different from the classical Lifshitz/Slyozov/Wagner kinetics at vanishing volume fractions (~0%) as well as from the kinetics of grain growth in single-phase systems (100%). The team conducts a combination of theoretical, computational and experimental studies. Specific research activities include: (1) developing a new theory for phase coarsening at ultra-high volume fractions; (2) conducting large-scale phase-field simulations of complex three-dimensional (3D) microstructural evolution that will yield important information such as coarsening rates, the temporal evolution of particle-size distributions and correlation functions, etc.; (3) measuring the 3D coarsening behavior of real two-phase systems in situ using time-resolved x-ray microtomography; and (4) carrying out quantitative comparisons between theory, simulation and experiments. A quantitative understanding of 3D phase coarsening kinetics is crucial to the optimization of processing conditions for controlling the final structure and properties of multiphase materials. The volume fraction of the coarsening phase is a critical factor in determining the coarsening kinetics. Due to the daunting theoretical and experimental challenges posed by complex microstructures at high-volume fractions of the coarsening phase, existing theoretical work has been limited to low volume fractions ( ~30%), and most experimental characterization has been carried out solely in two dimensions (2D) by metallographic sectioning. However, recent advances in theoretical modeling, computational simulation and 3D microstructural characterization offer an unprecedented opportunity to overcome the difficulties inherent in the study of coarsening at ultra-high volume fractions. The specific thrusts of this project therefore lie in improving our understanding of fundamental materials phenomena, in discovering new kinetics associated with complex microstructures, and in advancing the state of the art of simulation and experimental tools for 3D microstructural evolution and properties.Students and junior researchers participating in this project travel to the counterpart institutions across the Atlantic in order to immerse themselves in theoretical, computational and experimental studies of 3-D microstructural evolution. Via the student exchange program, these young researchers profit from the opportunity to develop skills that complement the intensive training in theory, simulation, or experiment that they receive at their home institutions, resulting in a multifaceted educational experience.This award is co-funded by the NSF Office of International Science and Engineering.

美国佛罗里达理工学院和宾夕法尼亚州立大学与乌尔姆大学和德国德累斯顿技术大学合作，解决相位粗化的根本问题。该项目的主要目标是了解超高 (90%) 体积分数下的相粗化动力学，预计该动力学与消失体积分数 (~0%) 下的经典 Lifshitz/Slyozov/Wagner 动力学有根本不同以及单相系统中晶粒生长动力学（100%）。该团队进行了理论、计算和实验相结合的研究。 具体研究活动包括：（1）开发超高体积分数相粗化的新理论； （2）对复杂的三维（3D）微观结构演化进行大规模相场模拟，这将产生重要的信息，例如粗化率、粒度分布的时间演化和相关函数等； (3) 使用时间分辨 X 射线显微断层扫描原位测量真实两相系统的 3D 粗化行为； (4)进行理论、模拟和实验的定量比较。对 3D 相粗化动力学的定量理解对于优化加工条件以控制多相材料的最终结构和性能至关重要。粗化相的体积分数是确定粗化动力学的关键因素。由于粗化相高体积分数下的复杂微观结构带来了令人畏惧的理论和实验挑战，现有的理论工作仅限于低体积分数（~30%），并且大多数实验表征仅在二维上进行(2D) 通过金相切片。然而，理论建模、计算模拟和 3D 微观结构表征方面的最新进展为克服超高体积分数粗化研究固有的困难提供了前所未有的机会。因此，该项目的具体目标在于提高我们对基本材料现象的理解，发现与复杂微观结构相关的新动力学，并推进 3D 微观结构演化和特性的模拟和实验工具的最先进水平。 学生和初级研究人员参与该项目的学生将前往大西洋彼岸的对应机构，沉浸在 3D 微观结构演化的理论、计算和实验研究中。通过学生交换计划，这些年轻的研究人员有机会发展技能，补充他们在国内机构接受的理论、模拟或实验强化培训，从而获得多方面的教育体验。该奖项由以下机构共同资助美国国家科学基金会国际科学与工程办公室。