CAREER: Understanding the Role of Nanoprecipitates in Advanced Metastable Titanium Alloys

职业：了解纳米沉淀物在先进亚稳钛合金中的作用

• 批准号: 2145844
• 负责人: Yufeng Zheng
• 金额: $ 52.06万
• 依托单位: Board of Regents, NSHE, obo University of Nevada, Reno
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-15 至 2023-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2145844&HistoricalAwards=false
• 关键词: CAREER; Understanding; Role; Nanoprecipitates; Advanced

NON-TECHNICAL SUMMARYIn materials science, strength is the measure of a material’s ability to bear a load or carry weight without failing. Alternatively, ductility is a measure of a material’s ability to bend, stretch or spread without breaking into pieces. Often, increasing the strength of a material results in a decrease of ductility and vice versa. This project supports fundamental research focused on the design of Titanium alloys that overcome this typical strength-to-ductility trade-off by carefully tailoring the elemental make-up of said alloys. This careful tailoring controls how specific parts of the metal are arranged on an atomic level to have a certain chemical composition and arrangement that increases the material’s strength without reducing the material’s overall ability to bend or stretch. This type of design is known as metastability engineering. This project investigates how parts of Titanium alloys having the same elemental makeup and atomic structure change with both temperature and chemical composition and how they deform under various circumstances. To explore this behavior, real-time and “after the fact” studies are performed using cutting edge equipment to discover connections between local chemistry, different environments and very small particles in the metal that are nanometers in size and have only recently been discovered in Titanium. The fundamental knowledge established in this project advances the ability to design lightweight Titanium alloys with both high strength and high ductility. Metastable titanium alloys are desirable for aerospace, automobile, bio-medical and chemical industries, due to their high strength-to-weight ratio, ability to absorb impact, resistance to chemical deterioration and compatibility with biological applications. As an example, relative to just one of these industries, improvements to these alloys can help to increase aircraft fuel efficiency, reduce fuel consumption, lower carbon emissions and ultimately, benefit the environment. This project also develops education modules for students in a K-12 Summer Camp as well as lab experiences for undergraduate and graduate students at the University of Nevada Reno. Both sets of activities feature high powered microscopes providing students from local Reno communities exposure to science and technology while also providing opportunities for women and underrepresented minorities to learn materials science for the purpose of developing the future scientific workforce.TECHNICAL SUMMARYThis project aims to advance a novel alloy designing strategy known as metastability engineering, by studying microstructural evolution and deformation in metastable Titanium alloys. The project will identify the critical role of the recently discovered, orthorhombic nano-precipitate, O prime (O’) in the spatially confined phase transformations of Titanium and its alloys. Advanced ex-situ and in-situ characterization techniques are employed to explore three specific phenomena: (i) The relationship between alloy composition and O’ nano-precipitates; (ii) The role of O’ in refining precipitate microstructure; and (iii) the role of O’ in regulating martensitic transformations. Multiscale ex- and in-situ experimental characterization using scanning electron microscopy, transmission electron microscopy, scanning transmission electron microscopy and atom probe tomography are used. This research progresses the ability to realize metastable alloys of Titanium having both high strength and high ductility. Education modules and outreach activities focused on electron microscopy creatively engage students in K-12, undergraduate and graduate level study. The education modules and activities are enhanced by a remote-controlled transmission electron microscope and a portable desktop scanning electron microscope to capture a wide range of interests and expose all to meaningful science. These education activities provide students in the neighboring community unprecedented access to science in real-time and offers to the student body at the University of Nevada, Reno a practical means of enhancing their in-class instruction with exposure to advanced characterization being performed at their institution. All activities assist with developing a future STEM workforce by generating interest in materials science to students at all ages.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.

非技术性总结在材料科学中，强度是衡量材料承受载荷或承载重量而不失效的能力。或者，延展性是材料弯曲、拉伸或伸展而不破碎成碎片的能力的量度。通常，增加材料的强度会导致延展性降低，反之亦然。该项目支持专注于钛合金设计的基础研究，通过仔细定制所述合金的元素组成来克服这种典型的强度-延展性权衡。这种精心的剪裁控制了金属的特定部分如何在原子水平上排列，以具有一定的化学成分和排列，从而增加材料的强度，而不会降低材料的整体弯曲或拉伸能力。这种类型的设计被称为亚稳态工程。本项目研究具有相同元素组成和原子结构的钛合金零件如何随温度和化学成分变化，以及它们在各种情况下如何变形。为了探索这种行为，使用尖端设备进行实时和“事后”研究，以发现局部化学，不同环境和金属中纳米尺寸的非常小的颗粒之间的联系，并且最近才在钛中发现。在这个项目中建立的基础知识提高了设计具有高强度和高延展性的轻质钛合金的能力。亚稳钛合金由于其高的强度重量比、吸收冲击的能力、耐化学变质性以及与生物应用的相容性而被期望用于航空航天、汽车、生物医学和化学工业。例如，相对于这些行业之一，对这些合金的改进可以帮助提高飞机燃油效率，降低燃油消耗，降低碳排放，并最终造福于环境。该项目还为K-12夏令营的学生开发了教育模块，并为内华达州里诺大学的本科生和研究生提供了实验室体验。这两组活动都以高倍显微镜为特色，为来自当地里诺社区的学生提供科学和技术的接触，同时也为妇女和代表性不足的少数民族提供学习材料科学的机会，以培养未来的科学劳动力。技术概述该项目旨在推进一种称为亚稳态工程的新型合金设计策略，通过研究亚稳钛合金的微观组织演变和变形。该项目将确定最近发现的正交纳米沉淀物O '（O'）在钛及其合金的空间受限相变中的关键作用。 采用先进的非原位和原位表征技术来探索三种特定现象：（i）合金成分与O'纳米沉淀物之间的关系;（ii）O'在细化沉淀物显微结构中的作用;（iii）O'在调节中的作用。马氏体转变。使用扫描电子显微镜，透射电子显微镜，扫描透射电子显微镜和原子探针断层扫描的多尺度前和原位实验表征。 该研究提高了实现具有高强度和高延展性的钛的亚稳合金的能力。教育模块和推广活动侧重于电子显微镜创造性地吸引学生在K-12，本科和研究生水平的研究。远程控制的透射电子显微镜和便携式桌面扫描电子显微镜增强了教育模块和活动，以捕捉广泛的兴趣，并使所有人都能接触到有意义的科学。这些教育活动为邻近社区的学生提供了前所未有的实时科学机会，并为内华达州大学里诺分校的学生提供了一种实用的方法，可以通过接触他们所在机构正在进行的高级表征来增强他们的课堂教学。所有活动都有助于培养未来的STEM劳动力，激发各个年龄段的学生对材料科学的兴趣。该奖项反映了NSF的法定使命，并且通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。