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

• 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

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.

非技术概述大块金属玻璃（BMG）是一类相当新的先进材料，具有非结晶（玻璃状）内部结构。它们不包含金属中常见的晶体相关缺陷。这种特殊的结构赋予BMG许多特性（例如，强度、硬度、弹性、耐磨性和耐腐蚀性），其性能上级许多金属。这种差异创造了极大地改善许多工程应用中广泛使用的许多金属的性能的潜力。然而，BMG面临的一个重大挑战是其有限的弯曲和拉伸能力。即使当它们断裂时，BMG在失效之前也没有显示出显著的拉伸或弯曲的证据。一些BMG已经表现出良好的延展性，但它们通常很难制成大尺寸或需要昂贵、有毒和/或难以找到的元素。设计具有良好延展性、可规模化生产且不使用有毒或难以获得的元素的BMG是该领域的一个突出问题。该项目通过研究主要研究者最近发现的铜基BMG中原子尺度的变形机制来应对这一挑战。这些铜基BMG具有高强度、良好延展性、优异的可制造性和工程友好成分的卓越组合。了解这些BMG弯曲，拉伸和最终失败的方式，将有助于未来发现其他同样或更卓越的BMG，这些BMG将比我们目前使用的材料更好地满足社会对高性能材料的需求。该项目吸引多名研究生和本科生参与直接研究，并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。通过一个完善的暑期项目，该项目还涉及K-12学生，特别是来自服务不足的地区和团体，培养对材料科学的好奇心和兴趣，同时促进STEM教育的多样性，公平性和包容性。研究结果被用来丰富本科介绍材料科学课程在俄勒冈州州立大学。该项目还帮助美国成为BMG的领先研究场所，BMG是具有战略重要性的一类材料，在未来的国防和航空航天应用中具有潜在的游戏规则改变者。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。大块金属玻璃（BMG）受到这两方面的挑战。通过合金设计实现BMG中的良好延展性而不牺牲组合物的强度、可制造性和工程友好性是该领域的中心问题。这些挑战的一个重要障碍是缺乏对BMG中的原子尺度特征（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理解。该项目结合了实验和计算方法，研究了最近发现的Cu基BMG家族中的原子变形机制，这些Cu基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组合。通过同步加速器光束线和扫描电子显微镜的协调原位应变被用来跟踪在不同水平的应力和应变的新BMG中的原子键和剪切带的行为，以探测改变组合物对其变形行为的影响（通过原子键和剪切带）。分子动力学模拟和有限元建模，然后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那些键的强度。通过这种方式，研究人员正在阐明这种新型BMG中强度和延展性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。这些知识是未来BMG设计所需要的，具有良好的延展性和理想的附加性能组合。该项目还推进了材料塑性领域的基础材料科学，这些材料在极端应力下无法用普通金属，陶瓷或聚合物材料进行探索。该项目支持的研究生体验了一个独特的机会，了解材料宏观变形和原子尺度的行为，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生涯做好准备。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

项目成果

Atomic Mechanisms of Crystallization in Nano-Sized Metallic Glasses

纳米金属玻璃结晶的原子机制

• DOI: 10.3390/cryst13010032
• 发表时间: 2023
• 期刊: Crystals
• 影响因子: 2.7
• 作者: Xu, Donghua;Wang, Zhengming;Chen, Lei;Thaiyanurak, Tittaya
• 通讯作者: Thaiyanurak, Tittaya