Plasticity, Phase Transformations, and their Interaction under High Pressure in Silicon

硅中的塑性、相变及其在高压下的相互作用

基本信息

批准号：
1943710
负责人：
Valery Levitas
金额：
$ 50万
依托单位：
Iowa State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-05-01 至 2024-04-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1943710&HistoricalAwards=false
关键词：
Plasticity Phase Transformations their Interaction

项目摘要

The interaction between crystalline phase transformations and permanent plastic deformation under high pressure in materials is broadly found in several technological applications; however, knowledge of this phenomenon is scarce because of the specialized equipment needed to observe it. This award fills the gap by supporting an integrated experimental, theoretical, and computational study of this interaction in silicon. Silicon is chosen as a representative material because it exhibits numerous types of phase transformations and is widely used in electronics and micro-electromechanical systems, as well as solar cells. The knowledge gained on the fundamental aspects of phase transformation-plasticity interaction under high pressure will also have broader implications on the quantitative modeling and optimization of surface processes, such as polishing, turning, and scratching, for brittle semiconductors and ceramics. As part of the project, there will be opportunities to educate and train graduate and undergraduate students through special courses and research, parts of which will be conducted at the Argonne National Laboratory, with an emphasis on underrepresented students.The objective of this research is to investigate the effect of plastic flow on phase transformation under high pressure in silicon. Coupled in situ high-throughput experiments and modeling will yield quantitative characterization and understanding of how plastic straining drastically reduces the transformation pressure, promotes the formation of novel phases, retains high-pressure phases at ambient pressure, and changes transformation paths between different phases. Silicon samples will be compressed and sheared in a rotational diamond anvil cell. Synchrotron X-ray diffraction and absorption, Raman spectroscopy, and displacement measurements will be used for in-situ diagnostics of the deformation and transformation processes. A microscale phase field approach for coupled phase transformations and localized shear bands (e.g., due to dislocation pileups) will be developed and used to study the interplay between multiple phase transformations and mechanisms of plasticity in single grains and polycrystalline aggregates. Phase transformation criteria, strain-controlled kinetic equations, and the pressure- and plastic strain-dependent yield strengths of all phases and phase mixtures will be obtained from the experiments and incorporated in a macroscale phenomenological model. This model will be used in the finite element simulations of deformation-transformation processes in diamond anvils. A search for new phases will also be performed as an application of the computational framework.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.

材料在高压下的结晶相变与永久塑性变形之间的相互作用广泛存在于多种技术应用中；然而，由于观察这种现象需要专门设备，因此人们对这种现象的了解很少。该奖项通过支持对硅中这种相互作用的综合实验、理论和计算研究来填补空白。选择硅作为代表性材料是因为它表现出多种类型的相变，并广泛用于电子和微机电系统以及太阳能电池。在高压下相变-塑性相互作用的基本方面获得的知识也将对脆性半导体和陶瓷的表面工艺（例如抛光、车削和划痕）的定量建模和优化产生更广泛的影响。作为该项目的一部分，将有机会通过特殊课程和研究来教育和培训研究生和本科生，其中部分研究将在阿贡国家实验室进行，重点关注代表性不足的学生。这项研究的目的是研究高压下塑性流动对硅相变的影响。结合原位高通量实验和建模将产生定量表征和理解塑性应变如何大幅降低转变压力，促进新相的形成，在环境压力下保留高压相，以及改变不同相之间的转变路径。硅样品将在旋转金刚石砧室中被压缩和剪切。同步加速器X射线衍射和吸收、拉曼光谱和位移测量将用于变形和转变过程的原位诊断。将开发耦合相变和局部剪切带（例如，由于位错堆积）的微尺度相场方法，并用于研究单晶粒和多晶聚集体中多个相变和塑性机制之间的相互作用。相变标准、应变控制动力学方程以及所有相和相混合物的压力和塑性应变相关的屈服强度将从实验中获得，并纳入宏观唯象模型中。该模型将用于金刚石砧变形转变过程的有限元模拟。对新阶段的搜索也将作为计算框架的应用进行。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（26）

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 multiphase phase-field study of three-dimensional martensitic twinned microstructures at large strains

大应变下三维马氏体孪晶微观结构的多相相场研究

DOI：
10.1007/s00161-022-01177-6
发表时间：
2023-01
期刊：
Continuum Mechanics and Thermodynamics
影响因子：
2.6
作者：
Basak, Anup;Levitas, Valery I.
通讯作者：
Levitas, Valery I.

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：
10.1016/j.actamat.2022.118489
发表时间：
2023-01
期刊：
Acta Materialia
影响因子：
9.4
作者：
Javanbakht, Mahdi;Levitas, Valery I.
通讯作者：
Levitas, Valery I.

Nonlinear elasticity of prestressed single crystals at high pressure and various elastic moduli

高压预应力单晶的非线性弹性及各种弹性模量

DOI：
10.1103/physrevb.104.214105
发表时间：
2021-12
期刊：
Physical Review B
影响因子：
3.7
作者：
Levitas; Valery I.
通讯作者：
Valery I.

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

DOI：
10.1016/j.ijengsci.2022.103732
发表时间：
2022-08
期刊：
International Journal of Engineering Science
影响因子：
6.6
作者：
Jafarzadeh, Hossein;Farrahi, Gholam Hossein;Levitas, Valery I.;Javanbakht, Mahdi
通讯作者：
Javanbakht, Mahdi

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