Collaborative Research: Atomistic Mechanisms of Stabilizing Oxide Nanoparticles in Oxide-dispersion Strengthened Structural Materials

合作研究：氧化物弥散强化结构材料中氧化物纳米颗粒稳定的原子机制

• 批准号: 0906344
• 负责人: Alexandra Navrotsky
• 金额: $ 18.83万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0906344&HistoricalAwards=false
• 关键词: Collaborative; Research; Atomistic; Mechanisms; Stabilizing

NON-TECHNICAL DESCRIPTION: The survival of materials under conditions of high temperature and radiation is crucial to their application in nuclear energy, space, and other applications under extreme conditions. Metal alloys can be strengthened by the dispersion of small (nanoscale) oxide particles. Yttrium titanium oxide nanoparticles greatly enhance the thermo-mechanical and radiation-resistant properties of such oxide-dispersion strengthened (ODS) alloys. It is scientifically challenging but technologically necessary to understand the exceptionally-high stability of these nanoparticles under extreme environments in order to develop advanced structural materials with enhanced performance. By synergy of experimental efforts and multi-scale computer simulations, the researchers at RPI and UC Davis will advance the understanding and control of transformation and structural evolution of such nanoparticles. This research program will train both graduate and undergraduate students working in key fields of radiation effects and the development of advanced structural materials. Special efforts will be made to involve underrepresented students, particularly woman engineers, into science and engineering through various programs at RPI and UC Davis. The fundamental understanding will contribute to the development of a dual-level course of ?radiation effects and nuclear reactor materials? at RPI. Findings of this project will be disseminated to a wider audience through national and international conference presentations.TECHNICAL DETAILSBuilding on a synergy of experiments and atomistic simulations, the groups at RPI and UC Davis will target a scientific understanding of the phase stability of dispersed oxide nanoparticles under high temperature and intense radiation conditions. Y-Ti-O nanoparticles (e.g., Y2Ti2O7 and Y2TiO5) will be synthesized and exposed to different irradiation conditions using intense ion beams and to different temperatures, and the morphology and microstructure will be characterized thoroughly by transmission electron microscopy (TEM) techniques. Calorimetric measurements will investigate the thermodynamic stability of Y-Ti-O nanoparticles as a function of size, irradiation, and temperature. Atomistic computer simulations, including first principles calculations, classical molecular dynamics and kinetic Monte Carlo simulations, will probe synergistic effects of radiation and temperature on the structural evolution of oxide nanoparticles and their defect behavior. This fundamental understanding will reveal the underlying physics and chemistry that govern phase stability and defect behavior of Y-Ti-O nanoparticles and establish the basis for developing predictive models of how nanostructured materials behave under extreme conditions of intense radiation and high temperature. Based on such fundamental understanding, new science will evolve to design strategy in materials processing for strengthening of alloys by oxide nanoparticles.

非技术描述：高温和辐射条件下材料的存活对于它们在极端条件下的核能，空间和其他应用至关重要。通过小（纳米级）氧化物颗粒的分散体可以增强金属合金。氧化钛纳米颗粒大大增强了这种氧化物 - 散异的增强（ODS）合金的热机械和抗辐射性能。在极端环境下了解这些纳米颗粒的特殊稳定性，以便开发具有增强性能的先进结构材料，这在科学上具有挑战性，但在技术上是必要的。通过实验努力和多尺度计算机模拟的协同作用，RPI和UC Davis的研究人员将提高对此类纳米颗粒的转化和结构演化的理解和控制。该研究计划将培训研究生和本科生在辐射效应的关键领域和高级结构材料的发展。通过RPI和UC Davis的各种计划，将尽力使代表性不足的学生，尤其是女工程师参与科学和工程。基本的理解将有助于发展辐射效应和核反应堆材料的双层过程？在RPI。该项目的发现将通过国家和国际会议演讲将其传播给更广泛的受众。技术细节建立了实验和原子模拟的协同作用，RPI和UC Davis的小组将针对对高温和强度辐射条件下分散氧化物纳米粒子的相位稳定性的科学理解。 Y-Ti-O纳米颗粒（例如，Y2TI2O7和Y2TIO5）将合成并使用强烈的离子束和不同的温度暴露于不同的辐射条件，并且将通过透射电子（TEM）技术彻底表征形态和微观结构。量热测量将研究Y-Ti-O纳米颗粒的热力学稳定性，这是大小，照射和温度的函数。原子计算机模拟，包括第一原理计算，经典分子动力学和动力学蒙特卡洛模拟，将探测辐射和温度对氧化物纳米颗粒及其缺陷行为的结构演化的协同作用。这种基本的理解将揭示Y-TI-O纳米颗粒的相稳定性和缺陷行为的基本物理和化学，并为开发纳米结构材料如何在极端辐射和高温条件下表现的预测模型建立了基础。基于这种基本的理解，新科学将发展为设计材料处理策略，以加强氧化物纳米颗粒的合金。