Collaborative Research: Nanoscale Structural and Compositional Instability-Driven Ductility in Refractory High-Entropy Alloys

合作研究：耐火高熵合金中纳米级结构和成分不稳定驱动的延展性

• 批准号: 2226508
• 负责人: Peter Liaw
• 金额: $ 15万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-12-01 至 2024-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2226508&HistoricalAwards=false
• 关键词: Collaborative; Research; Nanoscale; Structural; Compositional

NON-TECHNICAL SUMMARYThe engineering term for a material’s ability to be stretched by pulling, without breaking, is known as “ductility”. This collaborative research program is developing an atomistic understanding of the relationship between how refractory high-entropy alloys are made and their ductility response. These alloys, which have near equal amounts of multiple elements can have both high strength and high melting points and are ideal for elevated-temperature applications. A main drawback of these alloys however, is their low ductility at room temperature. This research project addresses this issue by seeking to increase the ductile strength of these alloys with twinning-induced plasticity and transition-induced plasticity. These approaches can result in changes to the crystal lattice known as distortions. To detect these lattice distortions as soon as possible and at the level of atoms, a data mining-based transmission electron microscopy approach is being developed. The study is assisted by a complimentary effort to make new materials, mechanically test these materials, and characterize their structure. Results are assisting in the design of new refractory alloys and the data mining microscopy technique can be applied to other materials as well, therefore a broad impact on other alloy research is expected. This project also integrates with an outreach effort across multiple levels tasked with contributing to a sustainable, adaptable, and globally competitive science, technology, and engineering workforce in the areas of alloy design and characterization. This research program is also seeking to increase public awareness of materials, data science, and related technologies, while simultaneously enriching the pool of underrepresented groups interested in science and engineering. TECHNICAL SUMMARYThis collaborative project explores the phase stability of group IV elements (Ti, Zr, and Hf) containing alloys and their related twinning-induced plasticity and transition-induced plasticity effects. Specifically, the research focuses on the precursors of phase transformation, in the form of structure-induced local lattice distortions and chemical short-range ordering in disordered multi-principal component alloys. The study is motivated by the promise of the high-entropy alloy concept for designing new alloys and the lack of understanding concerning the effects of chemical complexity on phase stability and physical properties. This research uses ductility in refractory high-entropy alloys as a model problem for the studies of body-centered-cubic (bcc) dynamic instability, and the effects of chemical disorder and lattice distortions on phase stability. This project is also further developing the cepstrum-based analysis of electron-diffuse scattering in electron nano-diffraction patterns. Correlation with lattice distortions and short-range ordering in selected alloys is being assisted by efforts to synthesize and characterize a collection of multi-principal element refractory alloys. Specifically, this study is answering the following questions: How can one determine local chemical ordering and its impact on dynamic instability? How do phase transformations manifest in a distorted lattice? How do the above two effects influence stress-induced martensitic transformation and deformation twinning? This project also supports the goal of contributing to a globally competitive workforce in STEM while also enriching the pool of underrepresented groups who will be participants in such a workforce.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.

非技术总和工程术语，指的是一种材料通过拉伸而不断裂的能力，称为“延展性”。这一合作研究计划正在发展一种原子学上的理解，即耐火高熵合金的制造方式与其延展性响应之间的关系。这些合金具有几乎等量的多种元素，可以同时具有高强度和高熔点，是高温应用的理想选择。然而，这些合金的一个主要缺点是在室温下的延展性较低。本研究项目通过寻求提高这些具有孪生诱发塑性和相变诱导塑性的合金的延性强度来解决这一问题。这些方法可能导致被称为扭曲的晶格变化。为了尽快在原子水平上检测这些晶格扭曲，一种基于数据挖掘的透射电子显微镜方法正在被开发。这项研究得到了一项有益的努力，即制造新材料、对这些材料进行机械测试并表征它们的结构。研究结果有助于新型耐火合金的设计，数据挖掘显微技术也可应用于其他材料，因此有望对其他合金的研究产生广泛影响。该项目还与跨多个层次的外联工作相结合，任务是在合金设计和表征领域促进可持续、适应性强和具有全球竞争力的科学、技术和工程劳动力。这项研究计划还寻求提高公众对材料、数据科学和相关技术的认识，同时丰富对科学和工程感兴趣的代表性不足的群体。技术总结这个合作项目探索了含有IV族元素(钛、锆和氢)的合金的相稳定性及其相关的孪生诱导塑性和相变诱导塑性效应。具体地说，研究重点是无序多主成分合金中结构诱导的局域晶格扭曲和化学短程有序等相变的先驱物。这项研究的动机是高熵合金概念在设计新合金方面的前景，以及对化学复杂性对相稳定性和物理性质的影响的缺乏了解。本研究以难熔高熵合金的延性为模型问题，研究体心立方(BCC)动力学不稳定性，以及化学无序和晶格扭曲对相稳定性的影响。该项目还在进一步发展基于倒谱的电子纳米衍射图中的电子扩散散射分析。通过努力合成和表征一系列多主元耐火合金，有助于与所选合金中的晶格扭曲和短程有序化相关。具体地说，这项研究回答了以下问题：如何确定局部化学有序性及其对动态不稳定性的影响？相变是如何在扭曲的晶格中表现出来的？这两种效应对应力诱发马氏体相变和形变孪晶有何影响？该项目还支持为STEM的全球竞争力劳动力做出贡献的目标，同时也丰富了将参与此类工作的代表不足的群体池。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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 superior fatigue strength in a powder-metallurgy titanium alloy via in-situ globularization during hot isostatic pressing

通过热等静压过程中的原位球化使粉末冶金钛合金实现优异的疲劳强度

• DOI: 10.1016/j.scriptamat.2023.115345
• 发表时间: 2023
• 期刊: Scripta Materialia
• 影响因子: 6
• 作者: Guo, R.P.;Cheng, M.;Zhang, C.J.;Qiao, J.W.;Cai, C.;Wang, Q.J.;Xu, D.S.;Xu, L.;Yang, R.;Shi, Y.S.
• 通讯作者: Shi, Y.S.

Self-lubricating behavior of a PdCuNiP glassy alloy by in-situ nanocrystallization during dry friction

• DOI: 10.1016/j.jnoncrysol.2023.122485
• 发表时间: 2023-09
• 期刊: Journal of Non-Crystalline Solids
• 影响因子: 3.5
• 作者: Nengbin Hua;Dehu Geng;Y. Ye;Zhenlong Liao;Qianting Wang;P. Dai;H. Fang;Lei Zhang;P. Liaw

A criterion of the critical threshold of the maximum shear stress in bulk metallic glasses with cryogenic thermal cycling by statistics in nanoindentation

• DOI: 10.1016/j.msea.2023.145031
• 发表时间: 2023-04
• 期刊: Materials Science and Engineering: A
• 作者: H. Zhang;Zhong Wang;P. Liaw;Junwei Qiao

Exploring multicomponent eutectic alloys along an univariant eutectic line

沿着单变共晶线探索多元共晶合金

• DOI: 10.1016/j.msea.2023.145136
• 发表时间: 2023
• 期刊: Materials Science and Engineering: A
• 作者: Jin, Xi;Xue, Zan;Mao, Zhouzhu;Guo, Ruipeng;Wang, Xuejiao;Shi, Xiaohui;Yin, Shaochun;Zhang, Min;Lan, Aidong;Liaw, Peter K.
• 通讯作者: Liaw, Peter K.

Thermal stability and deformation mechanisms in Ni-Co-Fe-Cr-Al-Ti-Nb-type nanoparticle-strengthened high-entropy alloys

• DOI: 10.1016/j.jmst.2023.05.044
• 发表时间: 2023
• 期刊: Journal of Materials Science & Technology
• 作者: J. Hou;J.Y. Zhang;J.X. Zhang;J. Luan;Y.X. Wang;B. Cao;Y. Zhao;Z. Jiao;X.J. Liu;W. Song;P. Liaw;T. Yang