DMREF/Collaborative Research: Low Cost, High Strength and Ductile Mg Alloys

DMREF/合作研究：低成本、高强度和延展性镁合金

• 批准号: 1922081
• 负责人: Derek Warner
• 金额: $ 45万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1922081&HistoricalAwards=false
• 关键词: DMREF; Collaborative; Research; Low; Cost

As the lightest of all structural metals, magnesium (Mg) alloys have great potential to be used in many applications where weight is critical to performance and efficiency, including the automotive, rail and aerospace industries. Yet wrought Mg alloys remain underutilized, due to a high processing cost. This Designing Materials to Revolutionize and Engineer our Future (DMREF) award supports fundamental research which could lead to efficient processing of high strength, high ductility Mg alloys through fundamental understanding of the relationships among processing, the micrometer-scale structure of the material, and performance. This project will educate a diverse group of students and postdoctoral fellows, providing them with the skills required to function within interdisciplinary teams comprised of computational and experimental researchers, as they perform work of benefit to the US manufacturing, transportation, and defense sectors.In this work, the researchers will investigate nanoscale solute clusters which form in the early stage of precipitation, known as Guinier-Preston (GP) zones, to understand how they contribute to materials properties, in particular to a recently observed increase in strain rate sensitivity. New computational methods that extend beyond transition state theory will be used to assess the kinetics of dislocation-GP zone interactions. Experimental assessments will be made using a combination of strain rate jump and repeated stress relaxation testing together with crystal plasticity modeling. The structure-property relationships established in this work will be used to guide alloy design strategies involving GP zones. This project also aims to predict the atomic structures and thermodynamic properties of GP zones in Mg alloys using first-principles-based computational approaches. To validate and guide these modeling efforts, transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) approaches are employed to probe the atomistic- and electronic-scale structure of the GP zones. These combined efforts will close the knowledge gap pertaining to the interplay between the free energies of solute mixing, phase formation and interfaces, and the coherency strains which are responsible for the formation and morphology of GP zones.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.

作为所有结构金属中最轻的，镁（Mg）合金具有巨大的潜力，可用于许多对性能和效率至关重要的应用，包括汽车，铁路和航空航天工业。然而，由于加工成本高，变形镁合金仍未得到充分利用。“设计材料以革新和工程我们的未来”（DMREF）奖支持基础研究，通过对加工、材料微米级结构和性能之间关系的基本理解，可以导致高强度、高延展性镁合金的有效加工。该项目将培养多样化的学生和博士后，为他们提供在由计算和实验研究人员组成的跨学科团队中发挥作用所需的技能，因为他们为美国制造业，交通运输业和国防部门开展有益的工作。在这项工作中，研究人员将研究在沉淀早期形成的纳米级溶质团簇，称为Guinier-Preston （GP）带，以了解它们如何影响材料性能，特别是最近观察到的应变速率敏感性的增加。超越过渡态理论的新计算方法将用于评估位错- gp区相互作用的动力学。实验评估将使用应变速率跳跃和重复应力松弛测试结合晶体塑性建模进行。在这项工作中建立的结构-性能关系将用于指导涉及GP区的合金设计策略。该项目还旨在利用基于第一性原理的计算方法预测镁合金GP区的原子结构和热力学性质。为了验证和指导这些建模工作，采用透射电子显微镜（TEM）和电子能量损失谱（EELS）方法来探测GP带的原子和电子尺度结构。这些共同的努力将缩小有关溶质混合、相形成和界面的自由能之间相互作用的知识差距，以及负责GP区形成和形态的相干应变。该奖项反映了美国国家科学基金会的法定使命，并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。

项目成果

The dual effect of surface adsorbates on fracture of calcite

表面吸附剂对方解石断裂的双重作用

• DOI: 10.1016/j.scriptamat.2023.115952
• 发表时间: 2024
• 期刊: Scripta Materialia
• 影响因子: 6
• 作者: Warner, Derek H.;Grutzik, Scott J.;Ilgen, Anastasia G.
• 通讯作者: Ilgen, Anastasia G.

Identifying crack tip position and stress intensity factors from displacement data

• DOI: 10.1007/s10704-023-00729-4
• 发表时间: 2023-07
• 期刊: International Journal of Fracture
• 影响因子: 2.5
• 作者: Swati Gupta;G. West;Mark A. Wilson;S. Grutzik;D. Warner

An Elementary Derivation of the Maximum Shear Stress in a Three Dimensional State of Stress

三维应力状态下最大剪应力的初等推导

• DOI: 10.1007/s10659-022-09948-7
• 发表时间: 2022
• 期刊: Journal of Elasticity
• 影响因子: 2
• 作者: Warner, Derek H.