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.

非技术摘要在过去的几千年中，人类已经学会了如何通过混合多种金属（即合金化）来制造坚固的材料。传统方法涉及在贱金属中添加少量合金元素。这一过程导致了最著名的金属合金——钢的诞生，它引发了工业革命，从而推动了人类文明技术进步的巨大飞跃。尽管在制造先进钢以及其他类型的更现代合金（例如用于高温应用的镍基合金和用于轻量化的铝和镁合金）方面取得了巨大进步，但关于这些材料响应的基本机制仍然存在许多基本问题至加载。这个问题的答案是设计承重结构（从建筑物和桥梁到汽车和飞机）时最重要的考虑因素。此外，随着现代技术的进步，迫切需要设计能够承受复杂且常常矛盾的条件的新材料，例如强度、成型性以及暴露于高温或腐蚀环境等极端情况。另一方面，冶金学的最新进展开辟了制造成分比传统合金复杂得多的多组分金属合金的可能性。该项目旨在建立合金成分、加工方式及其对负载的响应方式之间的严格关系，从而提供基于物理的预测路径来设计新合金以实现定制的结构性能。该程序结合了先进的建模和实验方法。将使用尖端计算技术来确定有趣的研究作品。 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以及变形过程中引起的内部材料缺陷的表征。此外，该计划还将提供一个机会，通过利用最先进的实验和计算技术的实践项目，吸引和培训从高中到本科和研究生的不同群体的学生，为下一代 STEM 教育做出贡献技术摘要针对多种成分提出了新颖的高通量计算和实验，以测试多组分 fcc 基合金的变形机制和随之而来的性能可以通过成分进行有利调整的假设。该提案旨在全面了解各种面心立方固溶体中的变形机制，包括与等原子成分的偏差，特别是探索孪生和六方密排马氏体效应可能有助于非凡应变硬化和极限强度潜力的成分。 因此，研究目标是：（1）采用新颖且高效的计算和组合实验方法来制造理想的合金； (2)了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联系； (4) 表征并模拟在高温下与异常硬化和动态应变时效相关的变形机制。 综合计算/实验框架将应用于广泛的 CrCoNi 三元合金以及该三元系统以外的合金，以便在基于面心立方的固溶体的化学性质与主动变形机制和机械行为。 PI Ghazisaeidi 最近开发的基于密度泛函理论 (DFT) 的新蒙特卡罗方法将用于预测相稳定性和偏析行为。 在这些计算的指导下，PI Mills 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。 该提案将通过原位力学实验挑战目前低堆垛层错能合金的测量，这将改善实验和 DFT 计算之间的相关性。 将成分与相稳定性和变形机制直接联系起来是必要的，具有相似或较低堆垛层错能（与 CrCoNi 相比）的 TWIP 钢不会表现出变形诱导马氏体（CrCoNi 也是如此），这一事实证明了这一点。 对这些复杂成分效应的研究将扩展到更高的温度，在机械响应中观察到强溶质相互作用的证据，例如异常硬化和锯齿状流动，但与这些相互作用相关的化学物质和变形机制尚未确定。 拟议的研究将可扩展到其他多元合金，包括许多重要的商业合金，如 IN825、MP35 和 Alloy 28，这些合金与最近出现的 fcc 基高熵合金具有成分共性，但目前缺乏详细的变形机制了解。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

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: 2019-02-01
• 期刊: Acta Materialia
• 影响因子: 9.4
• 作者: C. Slone;J. Miao;E. George;M. Mills
• 通讯作者: M. Mills

Deactivating deformation twinning in medium-entropy CrCoNi with small additions of aluminum and titanium

添加少量铝和钛使中熵 CrCoNi 中的变形孪晶失活

• DOI: 10.1016/j.scriptamat.2019.11.053
• 发表时间: 2020-03
• 期刊: Scripta Materialia
• 影响因子: 6
• 作者: Slone, C.E.;LaRosa, C.R.;Zenk, C.H.;George, E.P.;Ghazisaeidi, M.;Mills, M.J.
• 通讯作者: Mills, M.J.

Solid state welding of medium-entropy CrCoNi with heterogeneous, partially recrystallized microstructures

具有异质、部分再结晶微观结构的中熵 CrCoNi 固态焊接

• DOI: 10.1016/j.msea.2021.141425
• 发表时间: 2021-05-08
• 期刊: Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
• 影响因子: 6.4
• 作者: C. Slone;B. Barnett;B. Georgin;A. Vivek;E. George;G. Daehn;M. Mills
• 通讯作者: M. Mills

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

CrCoNi基中熵合金变形亚结构和应变硬化行为的有序效应

• DOI: 10.1016/j.actamat.2021.116829
• 发表时间: 2021-05
• 期刊: Acta Materialia
• 影响因子: 9.4
• 作者: Miao, Jiashi;Slone, Connor;Dasari, Sriswaroop;Ghazisaeidi, Maryam;Banerjee, Rajarshi;George, Easo P.;Mills, Michael J.
• 通讯作者: Mills, Michael J.

Elevated temperature microstructure evolution of a medium-entropy CrCoNi superalloy containing Al,Ti

含Al、Ti中熵CrCoNi高温合金的高温微观组织演化

• DOI: 10.1016/j.jallcom.2019.152777
• 发表时间: 2020-03-15
• 期刊: Journal of Alloys and Compounds
• 影响因子: 6.2
• 作者: C. Slone;E. George;M. Mills
• 通讯作者: M. Mills