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Defect dynamics in energy materials

能源材料中的缺陷动力学

基本信息

批准号：
EP/R005974/1
负责人：
Steve Fitzgerald
金额：
$ 104.05万
依托单位：
University of Leeds
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2018
资助国家：
英国
起止时间：
2018 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FR005974%2F1
关键词：
Defect dynamics energy materials

项目摘要

Advanced materials form the cornerstone of many emerging technologies, from next-generation energy production, transport and defence, to prosthetics and targeted drug delivery. Some of these eg. fusion energy require materials that do not yet exist, because the operating environment is so ferocious: high temperatures, corrosive environments and intense radiation mean no currently available material can be used. Theoretical modelling and predictive computer simulations are crucial steps in the development of new materials, since they can provide deeper understanding of the complex processes at work, and reduce lead times in product development. All modelling and simulation techniques are based on approximations, which limit their range of applicability. Whilst they have served well in the past, the extreme conditions mentioned above mean that some of these simplifying approximations no longer apply, and new techniques are required. The aims of this project are to develop new modelling approaches and simulation methods that are capable of handling the conditions, and apply them to unsolved problems in nuclear materials science. The most precise simulation methods currently available track every atom in the system. Although they can be very accurate, the computer power required to run them means they can only model a few cubic nanometres of material for a few nanoseconds. This cannot capture the large-scale, long-time processes that control material performance, and eventually decide, for example, how many years a nuclear reactor can be safely run before it needs to be replaced. At the other end of the scale, computer-aided design programs simulate reactor-sized components, but base this on simple rules on how materials behave. Ideally, these would be derived from microscopic simulations, but there is a huge gap in length and time-scales between them. The mesoscale simulations that this project will develop aim to bridge that gap. Over the last 60 years, particle physicists have developed powerful mathematical tools to understand quantum fluctuations. These tools can be modified to treat thermal fluctuations instead, and this will form the foundations of the new simulation methods. Instead of following every atom in the system, the new techniques will identify only the degrees of freedom that play important roles in the evolution of the material over time. These are the defects: impurity atoms, vacancies and self-interstitials (formed when atoms are knocked out of place in the regular lattice of eg. a metal) and dislocations (defect lines whose motion controls deformation). Though the new methods will be widely applicable, this project will focus on 3 case studies. This will answer technologically important questions, as well as testing the new techniques. The first case study concerns the clustering of Re atoms in W. Under the intense radiation of a fusion reactor, up to 5% of W atoms will transmute into Re. According to currently available modelling, the Re atoms should disperse through the W, yet experiments show clusters form. These clusters cause the material to become brittle, limiting its useful lifetime. The first case study will apply the new simulations to understand this. The second concerns the behaviour of dislocations under irradiation. This can be very different from their usual behaviour, and will strongly affect the mechanical properties of reactor materials. Current simulation methods ignore the single-atom defects, but these are crucial for understanding radiation effects. The new methods will track both kinds of defect, and help provide the understanding needed to mitigate and control them. The final case study will investigate the interaction of C atoms with dislocations. This is the process that makes iron into steel, and its importance can hardly be overstated. Although identified decades ago, important unanswered questions remain, and the new tools this project aims to develop will answer them.

先进材料构成了许多新兴技术的基石，从下一代能源生产、运输和国防，到假肢和靶向药物输送。其中一些EG。聚变能需要的材料目前还不存在，因为操作环境非常恶劣：高温，腐蚀性环境和强烈的辐射意味着目前没有可用的材料可以使用。理论建模和预测性计算机模拟是开发新材料的关键步骤，因为它们可以更深入地了解工作中的复杂过程，并缩短产品开发的交付时间。所有建模和模拟技术都是基于近似，这限制了它们的适用范围。虽然它们在过去很好地发挥了作用，但上面提到的极端条件意味着这些简化近似中的一些不再适用，并且需要新的技术。该项目的目的是开发能够处理这些条件的新的建模方法和模拟方法，并将其应用于核材料科学中尚未解决的问题。目前可用的最精确的模拟方法跟踪系统中的每个原子。虽然它们可以非常精确，但运行它们所需的计算机能力意味着它们只能在几纳秒内模拟几立方纳米的材料。这无法捕捉控制材料性能的大规模、长时间过程，并最终决定，例如，核反应堆在需要更换之前可以安全运行多少年。在尺度的另一端，计算机辅助设计程序模拟反应堆大小的组件，但基于材料行为的简单规则。理想情况下，这些将来自微观模拟，但它们之间的长度和时间尺度存在巨大差距。该项目将开发的中尺度模拟旨在弥合这一差距。在过去的60年里，粒子物理学家已经开发出强大的数学工具来理解量子涨落。这些工具可以修改为处理热波动，这将成为新模拟方法的基础。新技术将不再跟踪系统中的每一个原子，而是只识别在材料随时间演化中起重要作用的自由度。这些是缺陷：杂质原子，空位和自激（当原子在规则晶格中被撞出位置时形成的，例如。金属）和位错（其运动控制变形的缺陷线）。虽然新方法将广泛适用，但本项目将侧重于3个案例研究。这将回答技术上的重要问题，并测试新技术。第一个案例研究涉及Re原子在W中的团簇。在聚变反应堆的强辐射下，高达5%的W原子将转化为Re。根据目前可用的模型，Re原子应该分散在W中，但实验显示簇的形式。这些团簇导致材料变脆，限制了其使用寿命。第一个案例研究将应用新的模拟来理解这一点。第二个是关于辐照下位错的行为。这可能与它们的通常行为非常不同，并将强烈影响反应堆材料的机械性能。目前的模拟方法忽略了单原子缺陷，但这些对于理解辐射效应至关重要。新方法将跟踪这两种缺陷，并帮助提供缓解和控制它们所需的理解。最后一个案例研究将研究碳原子与位错的相互作用。这是把铁变成钢的过程，它的重要性怎么强调都不过分。虽然几十年前就已经确定了，但重要的未回答的问题仍然存在，该项目旨在开发的新工具将回答这些问题。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

A Turing instability in the solid state: void lattices in irradiated metals

固态的图灵不稳定性：辐照金属中的空晶格

DOI：
10.48550/arxiv.1903.09105
发表时间：
2019
期刊：
影响因子：
0
作者：
Noble M
通讯作者：
Noble M

Predicting the unobserved: A statistical mechanics framework for non-equilibrium material response with quantified uncertainty

预测未观察到的情况：具有量化不确定性的非平衡材料响应的统计力学框架

DOI：
10.1016/j.jmps.2022.104779
发表时间：
2022
期刊：
Journal of the Mechanics and Physics of Solids
影响因子：
5.3
作者：
Huang, Shenglin;Graham, Ian R.;Riggleman, Robert A.;Arratia, Paulo E.;Fitzgerald, Steve;Reina, Celia
通讯作者：
Reina, Celia

Structure and dynamics of crowdion defects in bcc metals

BCC 金属中拥挤缺陷的结构和动力学