Observing the crack tip behavior at the nanoscale during fracture of ceramics

• 成果类型: Article
• 署名作者: Gavalda-Diaz, Oriol; Emmanuel, Max; Berenov, Andrey; Marquardt, Katharina; Saiz, Eduardo; Giuliani, Finn
• 署名单位: Imperial College London; University of Nottingham; University of Oxford
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-15110
• DOI: 10.1073/pnas.2408292121
• 发表日期: 2024-10-22
• 关键词: monoclinic transformation; room-temperature; deformation; plasticity; toughness; strength; silicon

摘要

Ultimately, brittle fracture involves breaking atomic bonds. However, we still lack a clear picture of what happens in the highly deformed region around a moving crack tip. Consequently, we still cannot link nanoscale phenomena with the macroscopic toughness of materials. The unsolved challenge is to observe the movement of the crack front at the nanoscale while extracting quantitative information. Here, we address this challenge by monitoring stable crack growth inside a transmission electron microscope. Our analysis demonstrates how phase transformation toughening, previously thought to be effective at the microscale and above, promotes crack deflection at the nanolevel and increases the fracture resistance. The work is a first step to help connecting the atomistic and continuous view of fracture in a way that can guide the design of the next generation of strong and tough materials demanded by technologies as diverse as healthcare, energy generation, or transport.