Compositional Dependence of Deformation Mechanisms in Concentrated FCC Solid Solutions

浓 FCC 固溶体中变形机制的成分依赖性

• 批准号: 1905748
• 负责人: Michael Mills
• 金额: $ 53.02万
• 依托单位: Ohio 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: 2019-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1905748&HistoricalAwards=false
• 关键词: Compositional; Dependence; Deformation; Mechanisms; Concentrated

Non-Technical SummaryDuring the past millennia, humans have learned how to make strong materials by mixing more than one metal, i.e alloying. The traditional method has involved adding small amounts of alloying elements to a base metal. This process led to creation of the most famous metal alloy, steel, which is responsible for the industrial revolution and consequently a giant leap forward in technological advances of the human civilization. Despite great progress in making advanced steels as well as other types of more modern alloys, such as Ni base alloys for high temperature applications and Al and Mg alloys for light weighting, there still remain numerous fundamental questions regarding the underlying mechanisms through which these materials respond to loading. The answer to this question is the most important consideration when designing load bearing structures, from buildings and bridges to cars and airplanes. Moreover, with the modern technological advances, there is an urgent need to design new materials, capable of enduring complicated and often contradictory conditions, such as strength, formability and exposure to extreme situations such as high temperature or corrosive environments. On the other hand, recent progress in metallurgy has opened up the possibility of creating multicomponent metal alloys with much more complex compositions than conventional alloys. This program seeks to establish a rigorous relationship between alloy composition, the way it is processed, and how it responds to loading, thereby providing a physics-based predictive path to design new alloys for tailored structural properties. The program combines advanced modeling and experimental approaches. Interesting compositions for study will be identified using cutting-edge computational techniques. Experiments are designed to create predicted alloy compositions using efficient methods to rapidly explore a wide range of compositions, and characterization of internal material defects induced during deformation. In addition, this program will provide an opportunity to engage and train a diverse population of students from high school, to undergraduate and graduate levels, through hands on projects utilizing state of the art experimental and computational techniques to contribute towards educating the next generation of STEM workforce.Technical SummaryNovel, high-throughput computations and experiments are proposed over a wide range of compositions to test the hypothesis that deformation mechanisms and consequent properties in multicomponent fcc-based alloys can be favorably tuned by composition. This proposal seeks to develop a comprehensive understanding of deformation mechanisms in a wide range of fcc solid solutions, including deviation from equiatomic compositions, and specifically to explore compositions for which twinning and hcp martensite effects may contribute to extraordinary strain hardening and ultimate strength potential. Thus, the research objectives are to: (1) employ novel and efficient computational and combinatorial experimental approaches for creating desirable alloys; (2) understand the effect of stacking fault energy and relative fcc/hcp stability on the competing deformation mechanisms; (3) determine the evolution of deformation substructure with strain and the connection to remarkable strain hardening; and (4) characterize and model the deformation mechanisms operative at elevated temperature in association with anomalous hardening and dynamic strain aging. An integrated computational/experimental framework will be applied to a broad range of CrCoNi ternary alloys, and to alloys beyond this ternary system, in order to make a direct, quantitative connection between the chemistry of fcc-based solid solutions, and active deformation mechanisms and mechanical behavior. A new Monte Carlo method based on density functional theory (DFT) recently developed by PI Ghazisaeidi will be employed to predict phase stability and segregation behavior. Guided by these computations, PI Mills will conduct high-throughput experiments in order to reveal the complex relationships between composition, stacking fault energy, phase stability, and deformation mechanisms. This proposal will challenge present measurements in low stacking fault energy alloys through in situ mechanical experiments which will enable improved correlation between experiment and DFT calculation. Directly linking composition to phase stability and deformation mechanisms is necessary, as evidenced by the fact that TWIP steels with similar or lower stacking fault energies (when compared with CrCoNi) do not exhibit deformation-induced martensite (as does CrCoNi). Study of these complex composition effects will be extended to higher temperatures where evidence for strong solute interaction is observed in mechanical response, such as anomalous hardening and serrated flow, but the chemical species and deformation mechanisms associated with these interactions have yet to be identified. The proposed research will be extensible to other multicomponent alloys, including many important commercial alloys such as IN825, MP35, and Alloy 28 that share compositional commonality with the recently emerging fcc-based high entropy alloys, but presently lack detailed deformation mechanism understanding.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.

在过去的几千年里，人类已经学会了如何通过混合一种以上的金属来制造坚固的材料，即合金。传统的方法是在基体金属中加入少量的合金元素。这一过程导致了最著名的金属合金钢的诞生，钢是工业革命的罪魁祸首，也是人类文明技术进步的巨大飞跃。尽管在制造高级钢以及其他类型的更现代的合金（例如用于高温应用的Ni基合金和用于轻量化的Al和Mg合金）方面取得了很大进展，但是仍然存在关于这些材料响应于载荷的基本机制的许多基本问题。这个问题的答案是设计承重结构时最重要的考虑因素，从建筑物和桥梁到汽车和飞机。此外，随着现代技术的进步，迫切需要设计能够承受复杂且通常矛盾的条件的新材料，例如强度、可成形性和暴露于极端情况（例如高温或腐蚀性环境）。另一方面，冶金学的最新进展已经开辟了制造具有比传统合金复杂得多的组成的多组分金属合金的可能性。该计划旨在建立合金成分之间的严格关系，它的处理方式，以及它如何响应负载，从而提供一个基于物理的预测路径，设计新的合金定制的结构性能。该计划结合了先进的建模和实验方法。有趣的组成研究将确定使用尖端的计算技术。 实验旨在使用有效的方法创建预测的合金成分，以快速探索各种成分，并表征变形过程中诱导的内部材料缺陷。此外，该计划将提供一个机会，通过利用最先进的实验和计算技术的项目，为教育下一代STEM劳动力做出贡献，参与和培训从高中到本科和研究生水平的多样化学生群体。高通量的计算和实验提出了在广泛的组成范围内，以测试多组分fcc中的变形机制和随后的性质的假设，基合金可以有利地通过组成来调整。该提案旨在全面了解面心立方固溶体中的变形机制，包括偏离等原子组成，特别是探索孪晶和六方马氏体效应可能有助于非凡应变硬化和极限强度潜力的组合物。 因此，本研究的目标是：（1）采用新的和有效的计算和组合实验方法来创造理想的合金;（2）理解堆垛层错能和相对fcc/hcp稳定性对竞争变形机制的影响;（3）确定变形亚结构随应变的演变以及与显着应变硬化的关系;以及（4）表征并模拟高温下与异常硬化和动态应变时效相关的变形机制。 一个集成的计算/实验框架将被应用到广泛的CrCoNi三元合金，并超出此三元系的合金，以使fcc基固溶体的化学之间的直接，定量的连接，和主动变形机制和机械行为。一个新的Monte Carlo方法的基础上密度泛函理论（DFT）最近开发的PI Ghazisaeidi将用于预测相稳定性和偏析行为。 在这些计算的指导下，PI米尔斯将进行高通量实验，以揭示成分，堆垛层错能，相稳定性和变形机制之间的复杂关系。 这一建议将挑战目前的测量低堆垛层错能合金通过原位力学实验，这将使实验和DFT计算之间的相关性得到改善。 将成分与相稳定性和变形机制直接联系起来是必要的，这一事实证明，具有类似或更低堆垛层错能的TvS钢（与CrCoNi相比）不会表现出变形诱发马氏体（CrCoNi也是如此）。 这些复杂的组合物的影响的研究将被扩展到更高的温度下观察到的机械响应，如异常硬化和锯齿状流的强溶质相互作用的证据，但与这些相互作用的化学物种和变形机制尚未确定。 拟议的研究将可扩展到其他多组分合金，包括许多重要的商业合金，如IN 825，MP35和Alloy 28，它们与最近出现的fcc基高熵合金具有成分共性，但目前缺乏详细的变形机制的理解。该奖项反映了NSF的法定使命，并已被认为是值得支持的，通过评估使用基金会的智力价值和更广泛的影响审查标准。

项目成果

Achieving ultra-high strength and ductility in equiatomic CrCoNi with partially recrystallized microstructures

• DOI: 10.1016/j.actamat.2018.12.015
• 发表时间: 2019-02-15
• 期刊: ACTA MATERIALIA
• 影响因子: 9.4
• 作者: Slone, C. E.;Miao, J.;Mills, M. J.
• 通讯作者: Mills, M. J.

Ordering effects on deformation substructures and strain hardening behavior of a CrCoNi based medium entropy alloy

• DOI: 10.1016/j.actamat.2021.116829
• 发表时间: 2021-04-01
• 期刊: ACTA MATERIALIA
• 影响因子: 9.4
• 作者: Miao, Jiashi;Slone, Connor;Mills, Michael J.
• 通讯作者: Mills, Michael J.

SEM & STEM multi-scale characterization of fatigue damage in CrCoNi medium-entropy alloy with fully recrystallized microstructure.

扫描电镜

• DOI: 10.1017/s1431927620020851
• 发表时间: 2020
• 期刊: Microscopy and microanalysis
• 影响因子: 2.8
• 作者: Mazánová, V.;Heczko, M.;Slone, C.E.;Kuběna, I.;Tobiáš, J.;George, E.P.;Kruml, T.;Polák, J.;Mills, M.J.
• 通讯作者: Mills, M.J.

Elemental segregation to lattice defects in the CrMnFeCoNi high-entropy alloy during high temperature exposures

• DOI: 10.1016/j.actamat.2021.116719
• 发表时间: 2021-02-23
• 期刊: ACTA MATERIALIA
• 影响因子: 9.4
• 作者: Heczko, Milan;Mazanova, Veronika;Dlouhy, Antonin
• 通讯作者: Dlouhy, Antonin

Deactivating Deformation Twinning in Medium-Entropy CrCoNi with Small Additions of Aluminum and Titanium

• DOI: 10.1016/j.scriptamat.2019.11.053
• 发表时间: 2020-03
• 期刊: EngRN: Metals & Alloys (Topic)
• 作者: C. Slone;C. R. LaRosa;C. Zenk;E. George;M. Ghazisaeidi;M. Mills