CAREER: Assessing Low Temperature Phase Stability through Irradiation

职业：通过辐照评估低温相稳定性

• 批准号: 1653123
• 负责人: Julie Tucker
• 金额: $ 52.19万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1653123&HistoricalAwards=false
• 关键词: CAREER; Assessing; Low; Temperature; Phase

NON-TECHNICAL DESCRIPTION:Alloys in long-term service at moderately elevated temperatures (200-500°C), fall into a technological gap, where temperature effects are very slow but become significant over time. This temperature range is essential in many important technological industries such as aerospace, energy production and petrochemical plants. Over the period of decades, these materials can degrade and no longer perform as designed, potentially causing safety concerns. Laboratory studies of alloy degradation at these temperatures still take many years to perform and is often impractical. This project proposes to use irradiation as a tool to accelerate low temperature diffusion by creating more defects in the lattice. This method is expected to speed up the phase transformations that degrade properties by several orders of magnitude, which would make laboratory studies feasible. A long term thermal aging experiment will be performed to benchmark the irradiation results and computational simulations of atomic diffusion will be performed to help explain the differences between the two methods. Successful demonstration of the irradiation-enhanced method will allows us to identify the evolution of new, stable low-temperature phases, and to predict the service lifetime of alloys in service. Additionally, we expect to be able to use this knowledge to design new alloys that are better suited to resist long-term thermal degradation. This project is also designed to act as a vehicle for both recruiting and retaining a future generation of engineers and scientists from under-represented groups. By integration with two mentoring programs that bring Oregon high school, undergraduate and graduate students, and the professor together, a pyramid of mentorship in the laboratory is being created. TECHNICAL DESCRIPTION:Alloys in long-term service at temperatures in the range of 200-500°C, fall into a technological gap, where atomistic diffusion is very slow but becomes significant and phase diagrams are, as a consequence of the slow diffusion, usually incomplete. This temperature range is essential in many important technological industries such as aerospace, energy production and petrochemical plants. By using irradiation as a positive tool for materials research we expect to be able to accurately acquire these low-temperature data through irradiation-enhanced phase transformations. Successful demonstration of the validity of this method will allow the identification of new, stable low-temperature phases, and to validate kinetic transformation models within a practical timeframe. A parallel computational study will be used to explain differences between thermal and irradiation-assisted phase transformation and give fundamental insight into the mechanisms that control the transformation in the Ni-Cr-Fe system. In turn, the design of new alloys better suited to meet forthcoming technological needs can be expected to become possible. The research components of this project advance work of the scientific community by generating an improved thermodynamic database for the Ni-Cr-Fe system and implementing it within a commercial software package. This project supports the broader goal of training the future materials workforce by arming them with state-of-the-art experimental methods and theoretical approaches for studying phase transformations. Additionally, this project will help to increase diversity in STEM fields through research opportunities for under-represented high school and undergraduate student groups through two different outreach programs. These research opportunities and a newly-developed didactic class will encourage students to explore opportunities in materials science, specifically metallurgy.

非技术描述：在中度升高的温度（200-500°C）中长期服务的合金落入技术差距，温度效应非常慢，但随着时间的推移会变得显着。在许多重要的技术行业，例如航空航天，能源生产和石化植物中，这种温度范围至关重要。在几十年的时间里，这些材料会降低，并且不再按设计，可能会引起安全问题。这些温度下合金降解的实验室研究仍然需要多年的时间才能进行，而且通常是不切实际的。该项目建议使用辐照作为工具，通过在晶格中产生更多缺陷来加速低温扩散。预计该方法将加快降低多个数量级降低性能的相变，这将使实验室研究可行。将进行长期的热老化实验，以基准测试原子差异的辐照结果和计算模拟，以帮助解释两种方法之间的差异。成功演示了辐射增强方法将使我们能够确定新的稳定低温阶段的演变，并预测服务中合金的服务寿命。此外，我们希望能够使用这些知识来设计更适合抵抗长期热降解的新合金。该项目还旨在充当招募和保留代表性不足群体的工程师和科学家的工具。通过与将俄勒冈高中，本科生和研究生以及教授一起融合在一起的两个心理计划，正在创建实验室中的心态金字塔。技术描述：在200-500°C范围内的长期服务中的合金落入技术差距，在技术差距中，由于缓慢的扩散，通常不完整，因此原子扩散非常慢，但相位图很大，相图是。在许多重要的技术行业，例如航空航天，能源生产和石化植物中，这种温度范围至关重要。通过使用辐照作为材料研究的积极工具，我们希望能够通过辐射增强的相变精确地获取这些低温数据。成功证明了该方法的有效性，将允许鉴定新的，稳定的低温阶段，并在实际时间范围内验证动力学转化模型。一项平行的计算研究将用于解释热和辅助相变之间的差异，并为控制NI-CR-FE系统转化的机制提供基本的见解。反过来，可以预期，可以更适合满足即将到来的技术需求的新合金的设计将成为可能。该项目的研究组件通过为NI-CR-FE系统生成改进的热力学数据库并在商业软件包中实施的研究组成部分。该项目通过使用最先进的实验方法和研究相变的理论方法来武装培训未来的材料劳动力的更广泛的目标。此外，通过两种不同的外展计划，该项目将通过对代表性不足的高中和本科生群体的研究机会来帮助提高STEM领域的多样性。这些研究机会和新开发的教学课将鼓励学生探索材料科学（特别是冶金学）的机会。

项目成果

Deformation Twinning Versus Slip in Ni-Based Alloys, Containing Pt2Mo-Structured, Ni2Cr-Typed Precipitates

• DOI: 10.1016/j.matdes.2021.109820
• 发表时间: 2021-05
• 期刊: Materials & Design
• 影响因子: 8.4
• 作者: H. T. Vo;K. Dang;F. Teng;Matthew M. Schneider;B. P. Eftink;S. Maloy;J. Tucker;L. Capolungo

The formation and evolution of Ni2Cr precipitates in Ni–Cr model alloys as a function of stoichiometry characterized by synchrotron x-ray diffraction

• DOI: 10.1016/j.msea.2022.143930
• 发表时间: 2022-09
• 期刊: Materials Science and Engineering: A
• 作者: N. Aerne;D. Sprouster;J. Tucker

Effect of stoichiometry on the evolution of thermally annealed long-range ordering in Ni–Cr alloys

化学计量对 Ni-Cr 合金热退火长程有序演化的影响

• DOI: 10.1016/j.mtla.2019.100453
• 发表时间: 2019
• 期刊: Materialia
• 影响因子: 3.4
• 作者: Teng, Fei;Sprouster, David J.;Young, George A.;Ke, Jia-Hong;Tucker, Julie D.
• 通讯作者: Tucker, Julie D.

Role of Fe in long-range ordered Ni2Cr precipitates in Ni-Cr-Fe model alloys during isothermal aging

• DOI: 10.1016/j.msea.2023.145162
• 发表时间: 2023-05
• 期刊: Materials Science and Engineering: A
• 作者: N. Aerne;D. Sprouster;J. Tucker

First-principles study of 3sp impurity (S, P, Si, Al) effects on vacancy-mediated diffusion in Ni and Ni-33Cr alloys

3sp 杂质（S、P、Si、Al）对 Ni 和 Ni-33Cr 合金中空位介导扩散影响的第一性原理研究

• DOI: 10.1016/j.commatsci.2022.111768
• 发表时间: 2022
• 期刊: Computational Materials Science
• 影响因子: 3.3
• 作者: Ke, Jia-Hong;Tucker, Julie D.
• 通讯作者: Tucker, Julie D.