Atomic Scale Deformation Mechanisms in New Ductile Cu-Based Bulk Metallic Glasses with High Manufacturability

具有高可制造性的新型延展性铜基大块金属玻璃的原子尺度变形机制

基本信息

批准号：
2221854
负责人：
Donghua Xu
金额：
$ 49.97万
依托单位：
Oregon State University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2022
资助国家：
美国
起止时间：
2022-10-01 至 2025-09-30
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2221854&HistoricalAwards=false
关键词：
Atomic Scale Deformation Mechanisms New

项目摘要

NON-TECHNICAL SUMMARYBulk metallic glasses (BMGs) are a fairly new class of advanced material that has a non-crystalline (glassy) inner structure. They do not contain crystal-related defects as are common in metals. This special structure gives BMGs a host of properties (e.g., strength, hardness, resilience, wear- and cor-rosion-resistance) that can be superior to many metals. This difference creates the potential to dras-tically improve upon the performance of many metals widely used in several engineering applica-tions. However, one significant challenge facing BMGs is their limited ability to bend and stretch. Even when they break, BMGs do not show evidence of significant stretching or bending before failure. A few BMGs have demonstrated good ductility but they are often very difficult to make in large sizes or require elements that are either expensive, toxic and/or hard to find. Designing BMGs with good ductility, that can be manufactured at scale and which do not use toxic or hard to acquire elements is an outstanding question in the field. This project addresses this challenge by investigating the atomic-scale deformation mechanisms in Copper-based BMGs that were recently discovered by the principal investigator. These Cu-based BMGs possess an exceptional combination of high strength, good ductility, excellent manufacturability, and engineering-friendly compositions. Understanding the way these BMGs bend, stretch and ultimately fail, will help future discovery of other equally or more remarkable BMGs that will better serve the societal needs of high performance materials than the materials we currently use. This project engages multiple graduate and undergraduate students in direct research and prepares them for future materials-related careers in academia or industry. Through a well-established summer program, the project also involves K-12 students, particularly from underserved areas and groups, to cultivate curiosity and interest in materials science while promoting diversity, equity and inclusion in STEM education for all. Research findings are used to enrich an undergraduate Introduction to Materials Science course taught at Oregon State University. This project also aids the U.S. in being a place for leading research for BMGs which are a strategically important class of materials and a potential game changer in future defense and aerospace applications.TECHNICAL SUMMARYDuctility (or plasticity) often conflicts with strength in various types of materials. In addition, manufacturability and engineering-friendliness of composition is an additional common trade-off for engineering materials. Bulk metallic glasses (BMG) are challenged by both. Achieving good ductility in BMGs by alloy design without sacrificing strength, manufacturability and engineering-friendliness of composition are central issues in the field. A significant barrier to these challenges is the lack of understanding relative to how atomic-scale features (bonds, elements) in a BMG govern their macroscopic deformation and how to control these effects by design of their elemental compositions. This project combines experimental and computational methods to investigate atomic-sale deformation mechanisms in a recently discovered family of Cu-based BMGs which possess exceptional combinations of high strength, good ductility, excellent manufacturability and engineering-friendly compositions. Coordinated in-situ straining via a synchrotron beamline and a scanning electron microscope are used to track the behavior of the atomic bonds and shear bands in the new BMGs at different levels of stress and strain to probe the effects of changing composition on their deformation behavior (through atomic bonds and shear bands). Molecular dynamics simulations and finite element modeling are then used to analyze and interpret the experimental data. The project is expected to identify the atomic bonds primarily responsible for elastic deformation and determine the strength of those bonds chiefly responsible for plastic deformation and ductility. In this way, investigators are elucidating the fundamental origin of the unusual combination of strength and ductility in this new class of BMGs as well as revealing how alloy composition influences stress-driven atomic bond behavior and macroscopic deformation. Such knowledge is needed for the design of future BMGs with good ductility and ideal combinations of additional properties. This project also advances fundamental materials science in the area of materials plasticity at extreme stresses which cannot be explored with common metallic, ceramic or polymeric materials. Graduate students supported by the project experience a unique opportunity to learn about materials macroscopic deformatiion and atomic-scale behavior, master important experimental and computational techniques, and prepare for future careers in materials-related fields.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.

非技术摘要大块金属玻璃 (BMG) 是一种相当新型的先进材料，具有非结晶（玻璃状）内部结构。它们不包含金属中常见的与晶体相关的缺陷。这种特殊的结构赋予 BMG 一系列优于许多金属的特性（例如强度、硬度、弹性、耐磨性和耐腐蚀性）。这种差异有可能显着提高多种工程应用中广泛使用的金属的性能。然而，BMG 面临的一项重大挑战是其弯曲和拉伸的能力有限。即使 BMG 断裂，在失效前也不会表现出明显拉伸或弯曲的迹象。一些 BMG 已表现出良好的延展性，但它们通常很难制成大尺寸，或者需要昂贵、有毒和/或难以找到的元素。设计具有良好延展性、可大规模制造且不使用有毒或难以获取的元素的 BMG 是该领域的一个突出问题。该项目通过研究首席研究员最近发现的铜基 BMG 的原子级变形机制来解决这一挑战。这些铜基 BMG 具有高强度、良好的延展性、出色的可制造性和工程友好的成分的特殊组合。了解这些 BMG 弯曲、拉伸和最终失效的方式，将有助于未来发现其他同等或更出色的 BMG，这些 BMG 将比我们目前使用的材料更好地满足高性能材料的社会需求。该项目让多名研究生和本科生参与直接研究，为他们未来在学术界或工业界从事与材料相关的职业做好准备。通过完善的暑期项目，该项目还吸引了 K-12 学生，特别是来自服务欠缺地区和群体的学生，培养对材料科学的好奇心和兴趣，同时促进全民 STEM 教育的多样性、公平性和包容性。研究结果用于丰富俄勒冈州立大学本科生材料科学导论课程。该项目还帮助美国成为 BMG 研究的领先者，BMG 是一类具有重要战略意义的材料，也是未来国防和航空航天应用中潜在的游戏规则改变者。技术摘要各种材料的延展性（或塑性）经常与强度发生冲突。此外，组合物的可制造性和工程友好性是工程材料的另一个常见权衡。块状金属玻璃（BMG）受到两者的挑战。在不牺牲强度、可制造性和工程友好性的情况下，通过合金设计实现 BMG 的良好延展性是该领域的核心问题。这些挑战的一个重大障碍是缺乏对 BMG 中原子尺度特征（键、元素）如何控制其宏观变形以及如何通过设计其元素组成来控制这些效应的了解。该项目结合了实验和计算方法来研究最近发现的铜基 BMG 系列中的原子销售变形机制，这些 BMG 具有高强度、良好的延展性、优异的可制造性和工程友好的成分的特殊组合。通过同步加速器束线和扫描电子显微镜进行协调原位应变，用于跟踪新型 BMG 中原子键和剪切带在不同应力和应变水平下的行为，以探讨成分变化对其变形行为的影响。通过原子键和剪切带）。然后使用分子动力学模拟和有限元建模来分析和解释实验数据。该项目预计将确定主要负责弹性变形的原子键，并确定主要负责塑性变形和延展性的这些键的强度。通过这种方式，研究人员正在阐明这类新型 BMG 中强度和延展性的不寻常组合的根本起源，并揭示合金成分如何影响应力驱动的原子键行为和宏观变形。未来设计具有良好延展性和附加性能理想组合的 BMG 需要这些知识。该项目还推进了极限应力下材料塑性领域的基础材料科学，而普通金属、陶瓷或聚合物材料无法探索这一领域。受该项目支持的研究生体验了独特的机会来了解材料宏观变形和原子尺度行为，掌握重要的实验和计算技术，并为未来在材料相关领域的职业做好准备。该奖项反映了 NSF 的法定使命，并被视为值得通过使用基金会的智力优点和更广泛的影响审查标准进行评估来支持。