Investigation of fundamental creep behavior and mechanisms in a thermally stable nanocrystalline alloy

热稳定纳米晶合金基本蠕变行为和机制的研究

• 批准号: 1810431
• 负责人: Pedro Peralta
• 金额: $ 48.21万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1810431&HistoricalAwards=false
• 关键词: Investigation; fundamental; creep; behavior; mechanisms

Non-technical abstract:Structural materials used by power generation-reliant industries are often processed such that the amount of material imperfections present at small length scales is reduced. This approach has been quite successful; however, it is reaching the limits of what can be achieved, while new demanding applications require even higher material performance. This award supports fundamental research to look for the next generation of high performance materials for high temperature structural applications by using the opposite approach, i.e., to increase the number of imperfections at small, including atomic, length scales in such a way that deformation at high temperatures is impeded rather than enhanced by these imperfections. This requires a complete understanding of composition effects and processing conditions that can produce the high density of imperfections required and to make sure that they are retained during high temperature loading, since high temperatures tend to decrease the number of imperfections in a material. The physical principles that govern the relationship among processing, structure and mechanical properties in materials with such high number of defects as those proposed here are not well understood; hence, they will be studied in this project through a combination of experiments and modeling to produce new scientific knowledge in the field of structural materials. Furthermore, students in science and engineering at both undergraduate and graduate levels will participate in the research and be trained in state-of-the-art techniques to process, test, characterize and model structural material behavior, helping to educate the new generation of engineers and scientists in this field. Finally, the potential to understand how to produce a new generation of structural materials for high temperature applications with better properties than those currently available can have significant impacts and benefits to society. Technical abstract:Metal and alloys with a mean grain size below 100 nm have enhanced static strength compared to coarse-grained alloys and, hence, are very attractive for engineering applications. However, very few studies have addressed the fundamental mechanisms of microstructural evolution during time dependent deformation, limiting their practical use. This critical gap in knowledge has stemmed from the lack of consistency among various experimental conditions (processing methods, testing conditions, etc.) along with the grain growth observed during deformation. This indeterminate understanding hinders our ability to address the current need for advanced load-bearing structural materials in many important technologies where creep loading is common (e.g., power generation, propulsion). Motivated by this, the hypothesis that will be tested is that Ni-Y-Zr is a stable duplex system, wherein both grain boundary segregation (some solid solubility of Zr in Ni) and phase formation (e.g., Ni-Y precipitates) occur, leading to a microstructurally stable nanocrystalline alloy. Samples from the resulting material will be tested and characterized under a variety of loads and temperatures, unraveling true creep behavior and pertaining mechanisms of microstructural effects on creep of stable nanocrystalline materials. Furthermore, identification of these mechanisms will also enhance our understanding of microstructural instability commonly observed in nanocrystal materials at relatively low temperatures during time dependent deformation. In a broader context, the proposed work will lay the groundwork to address gaps in iterative materials design through coordinated modeling and experimental efforts across multiple length scales.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：依赖发电的工业使用的结构材料通常经过加工，以减少小尺寸材料的缺陷量。这种方法非常成功；然而，它正在达到所能达到的极限，而新的要求苛刻的应用程序对材料性能的要求甚至更高。该奖项支持基础研究，通过使用相反的方法来寻找用于高温结构应用的下一代高性能材料，即增加小尺度(包括原子长度)的缺陷数量，使高温下的变形受到这些缺陷的阻碍而不是增强。这需要完全了解可能产生所需高密度缺陷的成分效应和工艺条件，并确保在高温加载期间保留这些缺陷，因为高温往往会减少材料中的缺陷数量。在具有如此多缺陷的材料中，支配加工、结构和机械性能之间关系的物理原理还不是很清楚；因此，在这个项目中，将通过实验和建模相结合的方式来研究它们，以在结构材料领域产生新的科学知识。此外，本科生和研究生的理工科学生将参与这项研究，并接受最先进的技术培训，以处理、测试、表征结构材料行为并建立模型，帮助培养该领域的新一代工程师和科学家。最后，了解如何生产性能比现有材料更好的用于高温应用的新一代结构材料的潜力可以对社会产生重大影响和好处。技术摘要：与粗晶合金相比，平均晶粒度小于100 nm的金属和合金具有更高的静强度，因此在工程应用中非常有吸引力。然而，很少有研究涉及随时间变化的微观组织演变的基本机制，这限制了它们的实际应用。知识上的这一关键差距源于各种实验条件(加工方法、测试条件等)之间缺乏一致性。以及在变形过程中观察到的晶粒长大。这种不确定的理解阻碍了我们在许多重要技术中满足当前对先进承重结构材料的需求的能力，在这些技术中，蠕变载荷是常见的(例如，发电、推进)。在此基础上提出的假设是，Ni-Y-Zr是一个稳定的二元体系，其中既有晶界偏析(Zr在Ni中的某些固溶体)，也有相形成(例如，Ni-Y析出物)，从而获得了组织稳定的纳米晶合金。来自最终材料的样品将在各种载荷和温度下进行测试和表征，以揭示稳定的纳米晶体材料的真实蠕变行为和微结构对蠕变影响的相关机制。此外，对这些机制的识别也将加深我们对纳米晶体材料在随时间变化过程中在相对较低温度下观察到的微结构不稳定性的理解。在更广泛的背景下，拟议的工作将通过跨多个长度尺度的协调建模和实验努力，为解决迭代材料设计方面的空白奠定基础。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

Thermomechanical response of an ultrafine-grained nickel-yttrium alloy

• DOI: 10.1016/j.scriptamat.2020.06.068
• 发表时间: 2020-10
• 期刊: Scripta Materialia
• 影响因子: 6
• 作者: S. Srinivasan;C. Kale;B. Hornbuckle;K. Darling;Pedro Peralta;K. Solanki

Role of tantalum concentration on the high dose self-ion irradiation behavior of nanocrystalline binary alloys

• DOI: 10.1016/j.scriptamat.2022.115100
• 发表时间: 2023-01
• 期刊: Scripta Materialia
• 影响因子: 6
• 作者: S. Srinivasan;B. Hornbuckle;M. Chancey;K. Darling;Y.Q. Wang;K. Solanki

Thermo-Mechanical behavior of hypoeutectic Ni-Y-Zr alloys

• DOI: 10.1016/j.mtcomm.2024.108410
• 发表时间: 2024-02
• 期刊: Materials Today Communications
• 影响因子: 3.8
• 作者: Shruti Sharma;Saurabh Sharma;Samuel Moehring;Jun-Sang Park;Kiran Solanki;Pedro Peralta

An experimental and modeling investigation of tensile creep resistance of a stable nanocrystalline alloy

稳定纳米晶合金拉伸蠕变抗力的实验和建模研究

• DOI: 10.1016/j.actamat.2020.08.020
• 发表时间: 2020
• 期刊: Acta Materialia
• 影响因子: 9.4
• 作者: Kale, C.;Srinivasan, S.;Hornbuckle, B.C.;Koju, R.K.;Darling, K.;Mishin, Y.;Solanki, K.N.
• 通讯作者: Solanki, K.N.