Deformation of Metals under High Pressure: Multiscale Stress Fields, Plasticity, and Phase Transformations

高压下金属的变形：多尺度应力场、塑性和相变

基本信息

批准号：
1904830
负责人：
Valery Levitas
金额：
$ 45万
依托单位：
Iowa State University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-07-01 至 2022-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1904830&HistoricalAwards=false
关键词：
Deformation Metals under Pressure Multiscale

项目摘要

Non-technical abstract:Processes that involve high pressures and plastic deformations are quite common in material synthesis and technologies, e.g. in high-pressure torsion (or twisting). The main objective of these technologies is to produce high-pressure phases and nanostructures that possess unique physical properties important for engineering applications. However, an understanding of the physical mechanisms and ways to characterize and control simultaneous evolution of plastic deformations, phase transformations, and microstructure under high pressure is lacking. The goal of the project is to conduct the first coupled experimental, theoretical, and computational multiscale study of non-uniform stresses and strains, plastic flow, and phase transformations in several technically-important metals under high pressure and shear deformation. The experimental study will be performed in a rotational diamond anvil cell, a unique device in which material is compressed by two diamond anvils to high pressure and then twisted. The transparency of the diamonds allows for measurements of strains and study of various phase transformations directly in the loaded sample. The experimental study will be combined with advanced multiscale modeling, enabling extraction of all deformational and transformational material properties at high pressure. New science produced in the project is expected to impact existing and future technologies for synthesis of the nanograined high-pressure phases. Due to the interdisciplinary nature of the proposed work, two graduate and two undergraduate students will be trained to learn, develop, and apply cutting-edge experimental and computational techniques to a variety of complex systems.Technical abstract:Processes involving high pressures and plastic deformations are quite common in material synthesis and technologies, in nature (e.g. in geophysics), and in physical experiments. High pressure usually causes phase transformations in solids and plastic straining significantly changes the microstructure, thermodynamics, and kinetics of phase transformations. However, an understanding of the physical mechanisms and ways to characterize simultaneous evolution of dislocations and phase transformations under high pressure is lacking. The goal of the project is to conduct the first coupled experimental, theoretical, and computational multiscale study of stress and strain fields, dislocational plasticity, and strain-induced phase transformations in Zr, Fe, Ce, and CeP under high pressure and shear deformation. The experimental study will be performed in a rotational diamond anvil cell, a unique device in which material is compressed to high pressure and then twisted, while providing an opportunity for in situ measurements and study of various phase transformations and strains. Molecular dynamics and a nanoscale phase field approach will be used to model stress-field and nucleation at defects, coupled to the synchrotron X-ray microdiffraction measurements. The kinetics of strain-controlled phase transformations will be determined in terms of volume fraction of phases. At the macroscale, the evolution of the fields of the stress tensor, displacements, plastic strain, and the volume fraction of high-pressure phases within the entire sample in a rotational diamond anvil cell will be measured and simulated. As a result, all deformational and transformational material properties will be determined at high pressure. The hypothesis that the pure volumetric phase transformations in Ce and CeP are affected by plastic shear will be checked.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：涉及高压和塑性变形的过程在材料合成和技术中非常常见，例如在高压扭转（或扭转）中。这些技术的主要目标是生产具有对工程应用重要的独特物理性质的高压相和纳米结构。然而，人们对高压下塑性变形、相变和微观结构同时演化的物理机制和表征和控制方法缺乏了解。该项目的目标是对几种技术上重要的金属在高压和剪切变形下的非均匀应力和应变、塑性流动和相变进行首次耦合实验、理论和计算多尺度研究。该实验研究将在旋转金刚石砧室中进行，这是一种独特的装置，其中材料被两个金刚石砧压缩至高压，然后扭曲。金刚石的透明度允许直接在加载的样品中测量应变和研究各种相变。该实验研究将与先进的多尺度建模相结合，从而能够提取高压下的所有变形和相变材料特性。该项目产生的新科学预计将影响现有和未来的纳米晶高压相合成技术。由于拟议工作的跨学科性质，两名研究生和两名本科生将接受培训，学习、开发尖端实验和计算技术并将其应用于各种复杂系统。技术摘要：涉及高压和塑性变形的过程在材料合成和技术、自然界（例如地球物理学）和物理实验中非常常见。高压通常会引起固体中的相变，而塑性应变会显着改变相变的微观结构、热力学和动力学。然而，人们对高压下位错和相变同时演化的物理机制和方法缺乏了解。该项目的目标是首次对 Zr、Fe、Ce 和 CeP 在高压和剪切变形下的应力和应变场、位错塑性以及应变诱导相变进行实验、理论和计算耦合多尺度研究。该实验研究将在旋转金刚石砧室中进行，这是一种独特的装置，其中材料被压缩至高压，然后扭曲，同时为原位测量和研究各种相变和应变提供了机会。分子动力学和纳米级相场方法将用于模拟缺陷处的应力场和成核，并与同步加速器 X 射线微衍射测量相结合。应变控制相变的动力学将根据相的体积分数来确定。在宏观尺度上，将测量和模拟旋转金刚石砧室中整个样品内的应力张量、位移、塑性应变和高压相的体积分数场的演变。因此，所有变形和相变材料属性都将在高压下确定。 Ce 和 CeP 中的纯体积相变受塑性剪切影响的假设将得到检验。该奖项反映了 NSF 的法定使命，并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，被认为值得支持。

项目成果

期刊论文数量（33）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Athermal resistance to phase interface motion due to precipitates: A phase field study

沉淀物对相界面运动的非热阻：相场研究

DOI：
发表时间：
2022-06
期刊：
ArXivorg
影响因子：
0
作者：
Javanbakht, Mahdi;Levitas, Valery I.
通讯作者：
Levitas, Valery I.

Stationary dislocation motion at stresses significantly below the Peierls stress: Example of shuffle screw and 60∘ dislocations in silicon

远低于 Peierls 应力的应力下的稳态位错运动：硅中的洗牌螺旋和 60° 位错示例

DOI：
10.1016/j.actamat.2021.116623
发表时间：
2021-03
期刊：
Acta Materialia
影响因子：
9.4
作者：
Chen, Hao;Levitas, Valery I.;Xiong, Liming;Zhang, Xiancheng
通讯作者：
Zhang, Xiancheng

Imaging stress and magnetism at high pressures using a nanoscale quantum sensor

使用纳米级量子传感器对高压下的应力和磁性进行成像

DOI：
10.1126/science.aaw4352
发表时间：
2019-12
期刊：
Science
影响因子：
56.9
作者：
Hsieh, S.;Bhattacharyya, P.;Zu, C.;Mittiga, T.;Smart, T. J.;Machado, F.;Kobrin, B.;Höhn, T. O.;Rui, N. Z.;Kamrani, M.;et al
通讯作者：
et al

An atomistic-to-microscale computational analysis of the dislocation pileup-induced local stresses near an interface in plastically deformed two-phase materials

塑性变形两相材料界面附近位错堆积引起的局部应力的原子到微观计算分析

DOI：
10.1016/j.actamat.2022.117663
发表时间：
2022-03
期刊：
Acta Materialia
影响因子：
9.4
作者：
Peng, Yipeng;Ji, Rigelesaiyin;Phan, Thanh;Gao, Wei;Levitas, Valery I.;Xiong, Liming
通讯作者：
Xiong, Liming

Phase field theory for fracture at large strains including surface stresses

大应变（包括表面应力）断裂的相场理论