Collaborative Research: Deformation Mechanisms in Microstructurally Tailored High Strength Alloys Near the Ideal Limit

合作研究：接近理想极限的微观结构定制高强度合金的变形机制

• 批准号: 2310307
• 负责人: Timothy Rupert
• 金额: $ 42万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2310307&HistoricalAwards=false
• 关键词: Collaborative; Research; Deformation; Mechanisms; Microstructurally

NON-TECHNICAL DESCRIPTION: Materials with higher and higher strengths are often the target of materials scientists for structural engineering applications – stronger materials enable safer structures as well as lightweighting for more energy-efficient transportation. Several pathways are available for enhancing strength through control over defects in the material. However, efforts to-date have failed to bring material strengths anywhere near the holy grail of strengthening, referred to as the ideal strength. This failure has not come from a lack of materials engineering, nor would innovations in materials design or processing immediately solve the problem. Instead, prior approaches have been too limited in scope from the viewpoint of the material’s deformation physics, which is addressed in this research by considering novel design pathways for controlling material structure and, in turn, the defects that govern strength. The findings of this project are applicable to advanced materials with increased chemical complexity, which are desired for modern engineering applications. An interactive online learning module transcending traditional institutional barriers – denoted the Mechanics Interactive Teaming (MINT) initiative in engineering education – is being developed to engage students cooperatively at the partnering universities with new virtual learning modules focused on cutting-edge topics in materials science. The initial focus on graduate curricula is being broadened to reach undergraduates through the Women in Science and Engineering Program at Stony Brook University and further expanded for working professionals using relevant design problems through collaboration with the Advanced Casting Research Center at UC Irvine.TECHNICAL DESCRIPTION: This research enables materials with near-ideal strength by developing a fundamental understanding of dislocation nucleation and propagation as rate-limiting deformation mechanisms in nanostructured alloys where defect confinement and interaction with grain boundary and lattice solutes act as local barriers to plasticity. Specific research questions to be answered include: (i) what are the important transition states and associated energy barriers for dislocation nucleation at solute-decorated interfaces and for propagation within a nanoscale alloy crystal, (ii) how does interfacial structure and energy variation upon doping alter dislocation nucleation/propagation, and (iii) how do solute atoms inside the grain, which can potentially act as local pinning points but also alter the properties of the lattice, influence dislocation propagation? A practical hypothesis of this research is that the strength of nanocrystalline alloys can be maximized by synergistic doping to stabilize the grain boundaries against local plasticity and delay defect nucleation while simultaneously inhibiting dislocation propagation through the nanograin interiors. Using a combination of atomistic modeling, multi-modal structural characterization, and unique micromechanical testing, this hypothesis is being tested in nanostructured aluminum and copper alloys, where their intrinsically different stacking fault energies will provide access to different confined slip events. In a broad sense, this research will define new strengthening paradigms in nanoengineered metallic materials and establish the mechanistic underpinnings of solute-biased interfacial energy landscapes for understanding fundamental dislocation physics in confined slip environments.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.

非技术描述：具有较高优势的材料通常是材料科学家在结构工程应用中的目标 - 更强的材料可实现安全结构以及轻巧的运输。通过控制材料中的缺陷，可以使用几种途径来增强强度。但是，迄今为止的努力未能带来在加强圣杯附近的任何地方，被称为理想的力量。这种故障并非来自缺乏材料工程，材料设计或处理中的创新也不会立即解决该问题。取而代之的是，从材料的变形物理学的角度来看，先前的方法在范围上过于限制，这在本研究中可以通过考虑控制材料结构的新设计途径，进而解决了控制力量的缺陷。该项目的发现适用于具有增加化学复杂性的高级材料，这是现代工程应用所需的。一个超越传统机构障碍的交互式在线学习模块 - 表示机械师互动团队（MINT）的工程教育计划 - 正在开发旨在与学生合作地与新的虚拟学习模块合作地吸引学生与材料科学中的削减主题的新型虚拟学习模块。最初对毕业生课程的关注正在扩大，以通过斯托尼·布鲁克大学的科学和工程课程的妇女在本科生中获得本科生，并通过与UC Irvine的高级铸造研究中心合作，进一步扩展使用相关设计问题的工作专业人员。技术描述：这项研究能够通过对近乎理解的构建机制来实现近乎理解的材料，从而实现近距离的构造，从而实现了基本化的态度，从而实现了基础化的基础，从而实现了基础化。缺陷限制和与晶界和格子固体相互作用的合金充当局部塑性障碍。要回答的具体研究问题包括：（i）在固体装饰界面处的脱位成核的重要过渡状态和相关的能障碍，以及在纳米级合金晶体内传播中的传播，（ii）界面结构和能量变化在掺杂核的构成核的变化和固体范围内的构成和（iii）的属性，以及（iii）的属性，以及（iii）的属性，以及（iii）的属性，以及（iii）的属性，以及粒度的范围，以及粒度的范围，以及粒度的范围，粒子的属性，以及（iii）的属性，以及（iii ii can）的属性，晶格，影响错位传播？这项研究的一个实际假设是，可以通过协同掺杂来最大化纳米晶合金的强度，以稳定晶粒边界对局部可塑性和延迟缺陷核的延迟，同时通过纳米内部抑制脱位传播。使用原子建模，多模式结构表征和独特的微机械测试的结合，正在在纳米结构的铝和铜合金中测试该假设，在那里它们本质上不同的堆叠故障能量将提供对不同限制的滑移事件的访问。从广义上讲，这项研究将定义纳米工程金属材料的新加强范式，并建立了溶质偏见的界面能量景观的机械基础，以理解限制滑移环境中的基本脱位物理。该奖项颁发了NSF的法定任务，反映了通过评估范围的支持者，并通过评估了范围，并广泛地对基础进行了支持。