Fundamental Structural Processes of Relaxation and Shear Transformations in Metallic Glasses

金属玻璃松弛和剪切转变的基本结构过程

基本信息

  • 批准号:
    0904188
  • 负责人:
  • 金额:
    $ 49.95万
  • 依托单位:
  • 依托单位国家:
    美国
  • 项目类别:
    Standard Grant
  • 财政年份:
    2009
  • 资助国家:
    美国
  • 起止时间:
    2009-07-15 至 2013-09-30
  • 项目状态:
    已结题

项目摘要

This Award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).TECHNICAL SUMMARY:The metals we are familiar with are all crystalline, and their plasticity is well known to be carried by structural defects called dislocations. In contrast, the corresponding plastic flow mechanism in amorphous metals (i.e. ?bulk metallic glasses?, or BMGs) remains largely unresolved. This project is designed to uncover the fundamental structural processes responsible for the basic relaxation events in BMGs, including the thermal relaxation events and the initial inelastic relaxation events under stresses. For example, under imposed stresses, there must be structural origins responsible for the localized basic flow events, the so called ?shear transformations? (STs). There should be preferential ?flow defects? generated (the proposed ?shear transformation zones?, STZs), which play the role of dislocations in mediating the stress-driven atomic shuffling that carries the plastic strain. The structural origin of thermal relaxations and STs will be uncovered at the atomic level using molecular dynamics simulations. The locations of fertile sites for (cooperative) STs under stresses will be identified, based on specific local structural and dynamical properties, including the degree of local order, atomic-site stresses and free volume content. The atomistic ST mechanisms (the triggering events and cooperative atomic shear/shuffling), the STZ size (number of atoms involved) and the origin of this length scale, the fertility or propensity of local atoms for STs, the evolution of the short-to-medium range order during the ST and in the flow state, and the coalescing behavior of STZs in localization leading to later shear banding, will all be investigated. The kinetic pathway of the structural processes, in particular the associated transition barrier and its dependence on local structure, will be determined in terms of the potential energy landscape. The intellectual merit of this research lies in the resolution of a key structure ? (deformation) property relationship issue for amorphous metals.NON-TECHNICAL SUMMARY:Compared with conventional metals and alloys which are all crystalline, non-crystalline (amorphous) bulk metallic glasses (BMGs) show higher strength and yet can still sustain plastic flow (permanent strains and shape changes). The internal structures for amorphous (glassy) alloys are now on the atomic scale, without the ?dislocation? defects that carry the plastic deformation in the long-range regular lattice in crystalline metals. This project is designed to uncover how such glassy structures in BMGs evolve under stresses to control the yielding and ductility of the material. For broader impact, an educational effort will be made by compiling a simulation movie to enrich and advance the teaching of several materials science courses in which the concept of dislocation is used. The movie will demonstrate how a ?dislocation-less? flow process would be like, and contrast it with a ?dislocation motion in crystals? movie to help the students broaden their view about deformation processes in general. These movies will be produced by undergraduate students (assisted by faculty/graduate students) recruited into the laboratory to complete their Senior Design course, making use of their computer skills. In general, an understanding of the structure-deformation relationship has broad implications for the intensive work on metallic glasses currently ongoing around the world, especially for identifying what kind of glass structure/compositions would have a good combination of strength and ductility. Our research trains graduate students at the cutting edge of metals research. It builds on the knowledge acquired during the PI's previous projects and should hence be an efficient use of Federal funds. The results will be disseminated at conferences and in top journals.
该奖项是根据2009年美国复苏和再投资法案(公法111-5)资助的。技术概要:我们所熟悉的金属都是晶体,它们的塑性众所周知是由称为位错的结构缺陷携带的。相反,相应的塑性流动机制在非晶态金属(即?大块金属玻璃?(BMG)仍然基本上没有解决。该项目旨在揭示BMG中基本弛豫事件的基本结构过程,包括热弛豫事件和应力下的初始非弹性弛豫事件。例如,在外加应力下,必须有结构起源负责的局部基本流事件,所谓的?剪切变换(ST)。应该有优惠吗?流动缺陷?建议(The Proposed?剪切转变区,STZ),其在介导承载塑性应变的应力驱动的原子重排中起位错的作用。热弛豫和ST的结构起源将被发现在原子水平上使用分子动力学模拟。肥沃的网站(合作)ST应力下的位置将被确定,根据特定的局部结构和动力学性质,包括当地秩序的程度,原子网站的应力和自由体积含量。原子ST机制(触发事件和合作原子剪切/洗牌),STZ的大小(涉及的原子数)和这个长度尺度的起源,生育率或ST的本地原子的倾向,ST期间的短到中等范围的顺序和流动状态的演变,以及STZ在本地化导致后来的剪切带的聚结行为,都将被调查。结构过程的动力学途径,特别是相关的过渡障碍及其对局部结构的依赖性,将根据势能景观来确定。这项研究的智力价值在于解决了一个关键结构?非技术概述:与全部为结晶的常规金属和合金相比,非结晶(非晶)块状金属玻璃(BMG)显示出更高的强度,并且仍然可以维持塑性流动(永久应变和形状变化)。非晶(玻璃态)合金的内部结构现在是在原子尺度上,没有?错位?在晶体金属的长程规则晶格中进行塑性变形的缺陷。该项目旨在揭示BMG中的这种玻璃结构如何在应力下演变以控制材料的屈服和延展性。为了更广泛的影响,将通过编辑模拟电影来丰富和推进使用位错概念的几门材料科学课程的教学,从而进行教育努力。这部电影将展示如何一个?无错位?流程会是什么样子,并将其与一个?晶体中的位错运动影片,以帮助学生扩大他们的看法有关变形过程一般。这些电影将由本科生(由教师/研究生协助)招募到实验室完成他们的高级设计课程,利用他们的计算机技能。一般来说,对结构-变形关系的理解对于目前世界各地正在进行的金属玻璃的深入研究具有广泛的意义,特别是对于确定什么样的玻璃结构/组合物将具有良好的强度和延展性的组合。我们的研究培养研究生在金属研究的前沿。它建立在PI以前的项目中获得的知识的基础上,因此应该是联邦资金的有效利用。研究结果将在会议和顶级期刊上传播。

项目成果

期刊论文数量(0)
专著数量(0)
科研奖励数量(0)
会议论文数量(0)
专利数量(0)

数据更新时间:{{ journalArticles.updateTime }}

{{ item.title }}
{{ item.translation_title }}
  • DOI:
    {{ item.doi }}
  • 发表时间:
    {{ item.publish_year }}
  • 期刊:
  • 影响因子:
    {{ item.factor }}
  • 作者:
    {{ item.authors }}
  • 通讯作者:
    {{ item.author }}

数据更新时间:{{ journalArticles.updateTime }}

{{ item.title }}
  • 作者:
    {{ item.author }}

数据更新时间:{{ monograph.updateTime }}

{{ item.title }}
  • 作者:
    {{ item.author }}

数据更新时间:{{ sciAawards.updateTime }}

{{ item.title }}
  • 作者:
    {{ item.author }}

数据更新时间:{{ conferencePapers.updateTime }}

{{ item.title }}
  • 作者:
    {{ item.author }}

数据更新时间:{{ patent.updateTime }}

En (Evan) Ma其他文献

En (Evan) Ma的其他文献

{{ item.title }}
{{ item.translation_title }}
  • DOI:
    {{ item.doi }}
  • 发表时间:
    {{ item.publish_year }}
  • 期刊:
  • 影响因子:
    {{ item.factor }}
  • 作者:
    {{ item.authors }}
  • 通讯作者:
    {{ item.author }}

{{ truncateString('En (Evan) Ma', 18)}}的其他基金

Degree of short-to-medium-range order in metallic glasses
金属玻璃中短程至中程有序度
  • 批准号:
    1505621
  • 财政年份:
    2015
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Standard Grant
Russian-US Workshop on Mechanics of Advanced Materials
俄美先进材料力学研讨会
  • 批准号:
    0550016
  • 财政年份:
    2006
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Standard Grant
International Travel to Attend the Seventh International Conference on Nanostructured Materials; Wiesbaden, Germany; June 20-24, 2004
国际旅行参加第七届国际纳米结构材料会议;
  • 批准号:
    0434166
  • 财政年份:
    2004
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Standard Grant
Intrinsic Mechanical Properties of Nanocrystalline Metals
纳米晶金属的固有机械性能
  • 批准号:
    0355395
  • 财政年份:
    2004
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Continuing Grant
Nonequilibrium Alloys in Systems with Positive Heat of Mixing
具有正混合热的系统中的非平衡合金
  • 批准号:
    0080361
  • 财政年份:
    2000
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Continuing Grant
Properties of Consolidated Nanocrystalline Metals and Composites
固结纳米晶金属和复合材料的性能
  • 批准号:
    9877006
  • 财政年份:
    1999
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Continuing Grant
Solid-State Alloying and Amorphization of Immiscible Elements
难混溶元素的固态合金化和非晶化
  • 批准号:
    9896379
  • 财政年份:
    1998
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Continuing Grant
Solid-State Alloying and Amorphization of Immiscible Elements
难混溶元素的固态合金化和非晶化
  • 批准号:
    9613865
  • 财政年份:
    1997
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Continuing Grant
U.S.-China Cooperative Research: Formation and ThermodynamicStability of Metastable Phases in Selected Metals and Alloy Systems
中美合作研究:选定金属和合金体系中亚稳相的形成和热力学稳定性
  • 批准号:
    9423738
  • 财政年份:
    1995
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Standard Grant
Engineering Research Equipment: A Laboratory Hot Press
工程研究设备:实验室热压机
  • 批准号:
    9424324
  • 财政年份:
    1995
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Standard Grant

相似国自然基金

Understanding structural evolution of galaxies with machine learning
  • 批准号:
    n/a
  • 批准年份:
    2022
  • 资助金额:
    10.0 万元
  • 项目类别:
    省市级项目

相似海外基金

CAREER: Structural Estimation and Optimization for Partially Observable Markov Decision Processes and Markov Games
职业:部分可观察马尔可夫决策过程和马尔可夫博弈的结构估计和优化
  • 批准号:
    2236477
  • 财政年份:
    2023
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Standard Grant
Structural Racism and Black American Mental Health: Neurophysiological Mechanisms and Sociocultural Processes Promoting Resilience During the Transition to Adulthood
结构性种族主义和美国黑人心理健康:神经生理机制和社会文化过程促进成年过渡期间的复原力
  • 批准号:
    10473914
  • 财政年份:
    2022
  • 资助金额:
    $ 49.95万
  • 项目类别:
Structural Racism and Black American Mental Health: Neurophysiological Mechanisms and Sociocultural Processes Promoting Resilience During the Transition to Adulthood
结构性种族主义和美国黑人心理健康:神经生理机制和社会文化过程促进成年过渡期间的复原力
  • 批准号:
    10605341
  • 财政年份:
    2022
  • 资助金额:
    $ 49.95万
  • 项目类别:
Fundamental Processes of Instantaneous Structural Transformation of Crystal Defects Using Synergistic Effects of Irradiation Damage and Localized Laser Heating
利用辐照损伤和局部激光加热协同效应实现晶体缺陷瞬时结构转变的基本过程
  • 批准号:
    22K04783
  • 财政年份:
    2022
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Grant-in-Aid for Scientific Research (C)
GOALI: Structural and Topological Controls on Viscoelasticity and Relaxation Processes in Chalcogenide Glass-Forming Liquids
目标:硫族化物玻璃形成液体中粘弹性和弛豫过程的结构和拓扑控制
  • 批准号:
    1855176
  • 财政年份:
    2019
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Continuing Grant
Using diffusion tensor imaging to identify the structural neural correlates of visuospatial and motor skill learning processes
使用扩散张量成像来识别视觉空间和运动技能学习过程的结构神经相关性
  • 批准号:
    10065480
  • 财政年份:
    2018
  • 资助金额:
    $ 49.95万
  • 项目类别:
Exploration of stochastic phenomena disobeying the central limit theorem and development of innovative stochastic processes in the structural engineering
结构工程中不服从中心极限定理的随机现象的探索和创新随机过程的发展
  • 批准号:
    18K04334
  • 财政年份:
    2018
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Grant-in-Aid for Scientific Research (C)
Adsorption and desorption processes on beta-Ga2O3 and In2O3 surfaces studied via structural and thermo-/electrical investigations
通过结构和热/电研究研究 β-Ga2O3 和 In2O3 表面的吸附和解吸过程
  • 批准号:
    322072836
  • 财政年份:
    2016
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Research Grants
Development of the 3 dimensional structural multi-layer thin film preparation processes by the back side irradiation using powder target PLD method
粉末靶PLD法背面照射3维结构多层薄膜制备工艺的开发
  • 批准号:
    16K04999
  • 财政年份:
    2016
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Grant-in-Aid for Scientific Research (C)
Structural Biology of Calcium-Dependent Cellular Processes in Health and Disease
健康和疾病中钙依赖性细胞过程的结构生物学
  • 批准号:
    355132
  • 财政年份:
    2016
  • 资助金额:
    $ 49.95万
  • 项目类别:
    Operating Grants
{{ showInfoDetail.title }}

作者:{{ showInfoDetail.author }}

知道了