A Fundamental Study of Flow Mechanisms in Nanostructured Al Alloys and Intermetallic Compounds

纳米结构铝合金和金属间化合物流动机理的基础研究

• 批准号: 1810343
• 负责人: Megumi Kawasaki
• 金额: $ 34.67万
• 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: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1810343&HistoricalAwards=false
• 关键词: Fundamental; Study; Flow; Mechanisms; Nanostructured

Non-technical Abstract:The production of lightweight aluminum (Al) having high strength but sufficiently deformable without breaking under stress is technically challenging in manufacturing to accelerate their applications to automotive and aerospace industries. Early studies demonstrated that significant microstructural refinement through severe permanent deformation by a combination of high-pressure and twisting (torsion) leads to excellent hardness in bulk metals. Thus, the objective of this project is to scientifically investigate how to achieve high strength and good elongations to failure in conventional Al alloys and intermetallic compounds after the microstructural refinement process. The importance of this project is to understand the strengthening and flow mechanisms of the nanostructured Al systems after the high-pressure and torsion processing, and to determine how to overcome the paradox of strength and formability in bulk nanostructured Al alloys and its compounds. These results are expected to have an important positive impact because a mechanistic understanding of improving the mechanical properties in bulk metals will provide new opportunities for the development of strategies for the applications of Al alloys and lightweight engineering materials selections. The research requires proficiency in a variety of areas including physics, materials science, and mechanical engineering, making it challenging and rewarding for graduate and undergraduate students who will be supported by this program.Technical Abstract: Achieving both high strength and good ductility is currently not controllable in Al alloys and intermetallic compounds. Although grain refinement by high-pressure torsion (HPT) generally improves the hardness of metals, the strategies for achieving both high strength and ductility in metallic materials are available only under limited conditions: in precipitation-hardened alloys or in materials containing high densities of nano-twins. Except in age-hardenable compositions, it is a major challenge to introduce those into Al systems having high stacking fault energy. Thus, objectives of this project are to understand the plastic flow mechanisms for strengthening and plasticity in micro- and macro-scales in ultrafine microstructures, and to design strategies to increase both strength and ductility of ultrafine-grained Al systems processed by HPT. This project combines expertise in metallurgical research on nanocrystalline materials with advanced characterization methods of measurements by the novel nanoindentation technique and state-of-the-art X-ray and electron diffraction analysis. These techniques allow to identify the complex metal flow with concurrent texture changes in a time scale under ambient and elevated temperatures. The contribution of this project is significant because the acquired scientific knowledge of improving mechanical properties of bulk metals can be extended to a wide range of polycrystalline materials, which is expected to expand our current engineering materials selections and produce an increased U.S. competitiveness in advanced manufacturing.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：生产具有高强度但足够变形且在压力下不断裂的轻质铝(Al)是制造业中的技术挑战，以加速其在汽车和航空航天工业中的应用。早期的研究表明，通过高压和扭转(扭转)相结合的严重永久变形，可以显著细化组织，从而在大块金属中获得优异的硬度。因此，本项目的目标是科学地研究如何在常规铝合金和金属间化合物经过组织细化处理后获得高的强度和良好的断裂伸长率。本项目的重要意义在于了解纳米结构Al在高压和扭转处理后的强化和流动机制，并确定如何克服块体纳米结构Al合金及其化合物的强度和成形性悖论。这些结果有望产生重要的积极影响，因为对改善块体金属力学性能的机械理解将为铝合金应用和轻质工程材料选择的战略发展提供新的机会。这项研究需要精通包括物理、材料科学和机械工程在内的多个领域，这使得这项研究对将由该计划支持的研究生和本科生具有挑战性和回报。技术摘要：目前在铝合金和金属间化合物中实现高强度和良好的延展性是不可控制的。虽然高压扭转(HPT)细化晶粒通常会提高金属的硬度，但在金属材料中实现高强度和高塑性的策略只有在有限的条件下才能实现：在沉淀硬化合金中或在含有高密度纳米孪晶的材料中。除时效硬化组元外，将这些组元引入高层错能铝系是一大挑战。因此，本项目的目标是了解超细组织中微观和宏观尺度上的强化和塑性的塑性流动机制，并设计出提高HPT处理超细晶Al系统强度和塑性的策略。该项目将纳米晶体材料冶金研究的专业知识与先进的表征方法相结合，通过新的纳米压痕技术和最先进的X射线和电子衍射分析进行测量。这些技术允许识别在环境温度和高温下在时间尺度上具有并发纹理变化的复杂金属流动。该项目的贡献是巨大的，因为所获得的改善块状金属机械性能的科学知识可以扩展到广泛的多晶材料，这有望扩大我们目前的工程材料选择，并提高美国在先进制造方面的竞争力。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

On prominent TRIP effect and non-basal slip in a TWIP high entropy alloy during high-pressure torsion processing

• DOI: 10.1016/j.matchar.2021.111284
• 发表时间: 2021-08
• 期刊: Materials Characterization
• 影响因子: 4.7
• 作者: A. Chandan;P. Hung;K. Kishore;M. Kawasaki;J. Chakraborty;J. Gubicza

Strain-dependent phase transformation mapping of diffusion-bonded nanocrystalline aluminum-magnesium by high-energy synchrotron X-rays

高能同步加速器 X 射线对扩散结合纳米晶铝镁的应变相关相变图

• DOI: 10.1016/j.matlet.2022.132414
• 发表时间: 2022
• 期刊: Materials Letters
• 影响因子: 3
• 作者: Han, Jae-Kyung;Sugimoto, Kunihisa;Kawasaki, Megumi;Liss, Klaus-Dieter
• 通讯作者: Liss, Klaus-Dieter

Mechanical properties and structural stability of a bulk nanostructured metastable aluminum-magnesium system

• DOI: 10.1016/j.msea.2020.140050
• 发表时间: 2020-10
• 期刊: Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
• 影响因子: 6.4
• 作者: Jae-Kyung Han;K. Liss;T. Langdon;J. Jang;M. Kawasaki

Structural evolution during nanostructuring of additive manufactured 316L stainless steel by high-pressure torsion

• DOI: 10.1016/j.matlet.2021.130364
• 发表时间: 2021-07-06
• 期刊: MATERIALS LETTERS
• 影响因子: 3
• 作者: Han, Jae-Kyung;Liu, Xiaojing;Kawasaki, Megumi
• 通讯作者: Kawasaki, Megumi

Mechanical Bonding of Aluminum Hybrid Alloy Systems through High‐Pressure Torsion

• DOI: 10.1002/adem.201900483
• 发表时间: 2019-08
• 期刊: Advanced Engineering Materials
• 影响因子: 3.6
• 作者: M. Kawasaki;Seon-Ho Jung;Jeong-Min Park;Jongsup Lee;J. Jang;Jae-Kyung Han