CAREER: Understanding the Origins of Mechanical Hysteresis and Functional Fatigue in Martensitic Phase Transforming Materials

职业：了解马氏体相变材料中机械滞后和功能疲劳的起源

• 批准号: 2142302
• 负责人: Ashley Bucsek
• 金额: $ 71.98万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2142302&HistoricalAwards=false
• 关键词: CAREER; Understanding; Origins; Mechanical; Hysteresis

This Faculty Early Career Development (CAREER) project will elucidate long-lasting challenges facing materials that have reversibly tunable properties by way of a solid-to-solid phase transformation called martensitic phase transformation. For example, "switchable" multiferroics are materials that have distinct elastic, electric, and/or magnetic properties that can be reversibly "switched on or off" by inducing martensitic phase transformations. Switchable multiferroics have inspired novel energy conversion, energy harvesting, and actuator technologies, but hysteresis (loss of work capacity) and functional fatigue or failure remain major barriers for the cycle lifetime demands of these technologies. The goal of this research is to advance the understanding of mechanical hysteresis and functional fatigue in these materials through multiscale, multimodal in-situ experimentation. The award will also launch a comprehensive education and outreach platform with two main thrusts: (1) interactive extended reality (XR) learning tools for undergraduate and graduate courses as well as dissemination of research, and (2) hands-on demos on concepts of physics/mechanics for public outreach. These demos will also be used in workshops for underrepresented K–12 students through a Detroit-based summer camp.Martensitic phase transformations are the enabling mechanism behind the advanced performances of many diverse materials including "switchable" multiferroics, steels, elastomers, high entropy alloys, superconductors, and many materials at high strain rates. Due to the complexities of martensitic phase transformations, understanding these behaviors is a significant scientific challenge, and the hysteresis and functional fatigue associated with reversible martensitic transformations remain major technological barriers. The objective of this work is to understand mechanical hysteresis and functional fatigue by investigating the cyclic activation and propagation of martensitic microstructures. The approach is to resolve the hierarchical nature of the underlying micromechanics in situ, in 3D, and across five orders of magnitude in length scale, from the motion of the individual interfaces to the aggregate behavior of hundreds of grains. This multiscale approach will be achieved using multimodal 3D/4D in-situ characterization with dark-field X-ray microscopy, X-ray topo-tomography, and high-energy diffraction microscopy on magnesium-scandium shape memory alloys. The expected outcome is a new framework for understanding the mechanics of martensitic phase transforming materials that emerges from a multiscale understanding of stress-activated habit plane variant selection, incorporates the important role of defects, interfacial stress fields, and microstructural repeatability, and has broad implications for imperative cross¬cutting micromechanics challenges.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.

该教师早期职业发展（CAREER）项目将阐明通过称为马氏体相变的固相到固相变而具有可逆可调特性的材料所面临的长期挑战。例如，“可切换”多铁性材料是具有独特的弹性、电和/或磁特性的材料，其可以通过诱导马氏体相变可逆地“打开或关闭”。可切换多铁性材料激发了新型能量转换、能量收集和执行器技术，但磁滞（工作能力损失）和功能疲劳或故障仍然是这些技术循环寿命要求的主要障碍。这项研究的目标是通过多尺度、多模式的原位实验来增进对这些材料的机械滞后和功能疲劳的理解。该奖项还将推出一个综合教育和推广平台，该平台有两个主要目标：（1）用于本科生和研究生课程的交互式扩展现实（XR）学习工具以及研究传播，以及（2）用于公共推广的物理/力学概念的实践演示。这些演示还将在底特律夏令营中为代表性不足的 K-12 学生举办的研讨会中使用。马氏体相变是许多不同材料先进性能背后的实现机制，包括“可切换”多铁材料、钢、弹性体、高熵合金、超导体和许多高应变率材料。由于马氏体相变的复杂性，理解这些行为是一项重大的科学挑战，而与可逆马氏体相变相关的滞后和功能疲劳仍然是主要的技术障碍。这项工作的目的是通过研究马氏体微观结构的循环激活和传播来了解机械滞后和功能疲劳。该方法旨在以 3D 形式现场解决底层微力学的层次性质，并在长度尺度上跨越五个数量级，从单个界面的运动到数百个颗粒的聚合行为。这种多尺度方法将通过暗场 X 射线显微镜、X 射线拓扑断层扫描和高能衍射显微镜对镁钪形状记忆合金进行多模态 3D/4D 原位表征来实现。预期成果是一个用于理解马氏体相变材料力学的新框架，该框架源于对应力激活习惯平面变体选择的多尺度理解，结合了缺陷、界面应力场和微观结构可重复性的重要作用，并对势在必行的横切微观力学挑战具有广泛的影响。该奖项反映了 NSF 的法定使命，并通过使用 基金会的智力价值和更广泛的影响审查标准。

项目成果

3D in-situ characterization of dislocation density in nickel-titanium shape memory alloys using high-energy diffraction microscopy

• DOI: 10.1016/j.actamat.2024.119659
• 发表时间: 2024-01
• 期刊: Acta Materialia
• 影响因子: 9.4
• 作者: Wenxi Li;Sangwon Lee;Tianchi Zhang;Yuefeng Jin;Darren Pagan;Lee Casalena;Michael Mills;A. Bucsek