DMREF: Collaborative Research: Fundamentals of Short-Range Order-Assisted Alloy Design: Thermodynamics, Kinetics, Mechanics

DMREF：协作研究：短程有序辅助合金设计的基础：热力学、动力学、力学

• 批准号: 1921987
• 负责人: Takeshi Egami
• 金额: $ 42.69万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1921987&HistoricalAwards=false
• 关键词: DMREF; Collaborative; Research; Fundamentals; Short

It is well known that the ordering of atoms at the nanoscale dictates the properties and performance of materials, but knowledge of the quantitative relationships among properties, performance and structure - in particular the short-range ordering of atoms - is lacking for many structural alloys. Knowledge of these relationships has the potential to enable new high-strength, corrosion-resistant materials for use in transportation, energy, and infrastructure applications. This Designing Materials to Revolutionize and Engineer our Future (DMREF) award supports research to develop an improved fundamental understanding of short-range ordering, in order to identify guidelines for the design of new metallic materials with superior properties. Alloys with short-range order have characteristics of hard, but brittle intermetallics in the short-range, but also of soft pure metal or solid solutions, in the medium- to long-range. Despite classical understanding that suggests otherwise, there is increasing evidence that shows that short-range ordering can lead to unexpected improvements in mechanical properties. A short-range order-assisted alloy design concept will be explored as a new route to overcome the fundamental strength-toughness limitations in physical metallurgy. The overall goal of this research is to establish the fundamental understanding and the generic design rules that enable effective utilization of short-range order to realize damage-resistance in extreme environments. Concepts from this research are incorporated into educational modules in place at local science museums, and further educational benefits will stem from this work through the active participation of student researchers.This work aims to unravel what controls short-range order stabilities and characteristics, understand fundamentals of short-range order-assisted deformation micro/nano-mechanics, and design novel complex concentrated alloys that overcome current strength and toughness limits. It is necessary to understand how specific aspects of short-range order chemistry, size, and strength can be controlled, and how such variations would influence the interaction with dislocations. To this end, one of the most important challenges is regarding characterization. The typical size of the short-range ordered zones reaches the resolution limits of the conventional microscopy and diffraction tools such as the transmission electron microscopy, the atom probe tomography, and the x-ray diffraction. The research team will employ a novel, multi-pronged approach, combining theoretical modeling (ab-initio density functional theory calculation, Monte-Carlo simulation, and molecular dynamics), metallurgical processing (fabrication & testing), and atomically-resolved advanced structural characterization techniques (resonant x-ray scattering, in-situ scanning electron microscopy, and revolving scanning transmission electron microscopy) in order to overcome this challenge, and to link atomic-scale short-range order-characteristics to engineering properties at the macro-scale.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

众所周知，纳米级原子的顺序决定了材料的性质和性能，但是对于许多结构合金缺乏属性，性能和结构之间的定量关系，性能和结构之间的定量关系，尤其是原子的短距离顺序。这些关系的知识有可能使新的高强度，耐腐蚀的材料用于运输，能源和基础设施应用。这种设计材料彻底改变和设计我们的未来（DMREF）奖支持研究，以提高对短期订购的基本理解，以确定设计具有优质特性的新金属材料的准则。具有短距离顺序的合金具有在短距离中的硬质量但脆性的金属间代理，但也具有柔软的纯属或实心溶液，在中型到远距离中。尽管经典的理解是另外的，但越来越多的证据表明，短程排序可能会导致机械性能的意外改善。将探索短期订单辅助合金设计概念，以克服物理冶金中的基本强度限制限制。这项研究的总体目标是建立基本的理解和通用设计规则，使能够有效利用短期顺序以实现极端环境中的损害抗性。这项研究的概念被纳入当地科学博物馆的教育模块中，而进一步的教育益处将源于学生研究人员的积极参与这项工作。这项工作旨在揭开控制短距离订单稳定性和特征的控制，了解短期订单订单的基本面的基本面，这些基本范围订单构成的不适用的不适用的不适用的不适用的小型/纳米机电和设计的新型复杂性和设计的范围越来越多种组成的范围，从而使差异和设计变得越来越多样化。 有必要了解如何控制短期顺序化学，大小和强度的特定方面，以及这种变化如何影响与位错的相互作用。为此，最重要的挑战之一是关于表征。短距离有序区域的典型尺寸达到了传统显微镜和衍射工具的分辨率限制，例如透射电子显微镜，原子探针断层扫描和X射线衍射。 The research team will employ a novel, multi-pronged approach, combining theoretical modeling (ab-initio density functional theory calculation, Monte-Carlo simulation, and molecular dynamics), metallurgical processing (fabrication & testing), and atomically-resolved advanced structural characterization techniques (resonant x-ray scattering, in-situ scanning electron microscopy, and revolving scanning transmission electron显微镜）为了克服这一挑战，并将原子级的短期订单序列与宏观规模的工程特性联系起来。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛影响的审查标准通过评估来通过评估来支持的。