CAREER: Leveraging Plastic Deformation Mechanisms Interactions in Metallic Materials to Access Extraordinary Fatigue Strength.

职业：利用金属材料中的塑性变形机制相互作用来获得非凡的疲劳强度。

• 批准号: 2338346
• 负责人: jean-charles stinville
• 金额: $ 63.23万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-03-01 至 2029-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2338346&HistoricalAwards=false
• 关键词: CAREER; Leveraging; Plastic; Deformation; Mechanisms

NON-TECHNICAL SUMMARY:Metallic materials used in structural engineering are vital to a wide range of industries. However, many metals and alloys exhibit limited resistance to repeated loading (Fatigue), limiting their sustainability. Metallic materials under repeated loading localize deformation at the nanometer scale that ultimately leads to crack initiation and fracture. Pre-deformation under extreme temperatures is used in the present project to generate initial deformation states that hinder the localization of the deformation under repeated loading. First, the deformation behavior of metallic materials at the nanometer scale under extreme temperatures is determined. Then, through this fundamental understanding, deformation states from extreme temperature deformations that hinder the localization of the deformation when the material is subject to repeated loading are identified. This endeavor aims to equip current metals and alloys with the competitive edge and sustainability required to meet the ever-evolving needs of our society and advancing technology.TECHNICAL SUMMARY:The research initiative seeks to explore and identify the interactions of plastic deformation mechanisms in metallic materials. By focusing on beneficial interactions, remarkable fatigue strength in face-centered cubic materials can be achieved. This project will explore how plasticity localizes when various deformation mechanisms compete. State-of-the art in-situ characterization tools, adept at statistically and qualitatively determining plastic localization, is used to study the array of possible deformation mechanism interactions within metallic materials. Building on this knowledge, pre-deformation pathways at extreme temperatures are introduced to create initial plastic localization states that hinder cyclic irreversibility, a factor that governs material fracture under fatigue. By manipulating plastic localization at the nanoscale through deformation at extreme temperatures, the fatigue strength of structural metals is enhanced dramatically.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：结构工程中使用的金属材料对于许多行业都至关重要。然而，许多金属和合金对重复负载（疲劳）的抵抗力有限，限制了其可持续性。金属材料在重复载荷下会发生纳米级的局部变形，最终导致裂纹萌生和断裂。本项目使用极端温度下的预变形来产生初始变形状态，从而阻碍重复加载下变形的局部化。首先，确定金属材料在极端温度下纳米尺度的变形行为。然后，通过这一基本理解，识别出当材料受到重复载荷时阻碍变形局部化的极端温度变形的变形状态。这项努力旨在使当前的金属和合金具有竞争优势和可持续性，以满足我们社会不断发展的需求和先进技术。技术摘要：该研究计划旨在探索和确定金属材料中塑性变形机制的相互作用。通过关注有益的相互作用，面心立方材料可以获得显着的疲劳强度。该项目将探讨当各种变形机制竞争时塑性如何局部化。最先进的原位表征工具擅长统计和定性确定塑性局部化，用于研究金属材料内一系列可能的变形机制相互作用。基于这些知识，引入了极端温度下的预变形路径，以创建阻碍循环不可逆性的初始塑性局部化状态，循环不可逆性是控制疲劳下材料断裂的因素。通过在极端温度下变形来操纵纳米级的塑性局部化，结构金属的疲劳强度显着增强。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。