Self-Organization in Model Cu Alloys for High-temperature Irradiation Environments

高温辐照环境下模型铜合金的自组织

• 批准号: 1306475
• 负责人: Pascal Bellon
• 金额: $ 60万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1306475&HistoricalAwards=false
• 关键词: Self; Organization; Model; Cu; Alloys

TECHNICAL SUMMARY:The PIs utilize self-organization reactions to obtain materials that are intrinsically stable under high-temperature irradiation environments. Conventional materials degrade through embrittlement, segregation, creep, and swelling in such environments, caused by the unbalanced flow of point defects to sinks. In order to overcome these detrimental evolutions, self-organization reactions are used here to introduce a high density of stable point-defect traps, thus enhancing recombination. Two separate self-organization mechanisms are considered, involving the competition between ballistic mixing and thermal decomposition, and intra-cascade precipitation. By activating both mechanisms simultaneously, complex core/shell nanostructures are expected with vastly improved stability under irradiation at homologous temperatures as high as 0.80 and with improved mechanical properties. Model Cu-W-X ternary alloys (X = Ag, Fe, Ni) are used to test and validate the approach. Thin films of these alloys are characterized before and after ion irradiation with a combination of techniques, including XRD, TEM, atom probe tomography, and in situ electrical resistivity. Atomistic simulations, including kinetic Monte Carlo simulations that include the creation, recombination and elimination of point defects, are employed to identify the conditions for compositional patterns to remain dynamically stable at elevated temperature and under irradiation. The impact of the program is broadened by developing a new module for a senior laboratory course, highlighting nanoscale precipitation and ordering in thin films, by providing research experience for undergraduates, and by promoting faculty-student interactions and outreach activities through our departmental Material Advantage Chapter.NON-TECHNICAL SUMMARY:The proposed design for the future generations of advanced nuclear power systems rely on materials that need to operate at elevated temperatures and under prolonged irradiation. Current materials cannot operate safely, reliably, and economically in such harsh environments. The present research program proposes to utilize self-organization reactions to design materials that will produce complex nano-scale precipitates. By judicious choice of alloying elements, these nano-precipitates will be optimized to stabilize the microstructure and the mechanical properties of these materials. The resulting high-strength, high-temperature materials will also be of interest for other energy production systems. The research will provide education for two graduate and two undergraduate students, with an emphasis on advanced materials synthesis and characterization techniques and atomistic modeling. Special effort will be made to recruit female and underrepresented minority students. Outreach activities aimed at encouraging high-school students to pursue STEM careers will be initiated and coordinated with our departmental Material Advantage student chapter.

技术摘要：PI利用自组织反应获得在高温辐照环境下本质稳定的材料。传统材料在此类环境中会因脆化、偏析、蠕变和膨胀而降解，这是由点缺陷向汇点的不平衡流动引起的。为了克服这些有害的演化，这里使用自组织反应来引入高密度的稳定点缺陷陷阱，从而增强复合。考虑了两种独立的自组织机制，涉及弹道混合和热分解之间的竞争以及级联内沉淀。通过同时激活这两种机制，复杂的核/壳纳米结构有望在高达 0.80 的同源温度下辐照下大大提高稳定性，并具有改善的机械性能。 Cu-W-X 三元合金模型（X = Ag、Fe、Ni）用于测试和验证该方法。通过结合 XRD、TEM、原子探针断层扫描和原位电阻率等技术对这些合金的薄膜在离子辐照前后进行表征。原子模拟，包括动态蒙特卡罗模拟，包括点缺陷的产生、重组和消除，用于确定成分图案在高温和辐照下保持动态稳定的条件。通过为高级实验室课程开发一个新模块，强调薄膜中的纳米级沉淀和有序化，为本科生提供研究经验，并通过我们部门的材料优势章节促进师生互动和外展活动，扩大了该计划的影响。非技术摘要：未来几代先进核电系统的拟议设计依赖于需要在高温和长时间运行的材料。 辐照。目前的材料无法在如此恶劣的环境下安全、可靠、经济地运行。目前的研究计划建议利用自组织反应来设计能够产生复杂纳米级沉淀物的材料。通过明智地选择合金元素，这些纳米沉淀物将得到优化，以稳定这些材料的微观结构和机械性能。由此产生的高强度、高温材料也将引起其他能源生产系统的兴趣。该研究将为两名研究生和两名本科生提供教育，重点是先进材料合成和表征技术以及原子建模。将特别努力招收女性和代表性不足的少数族裔学生。旨在鼓励高中生追求 STEM 职业的外展活动将与我们部门的 Material Advantage 学生分会一起发起和协调。