Quantifying the Defect Character of Grain Boundaries with Traction based Descriptors
Abstract
Interfaces are ubiquitous in a wide range of natural and engineering materials, and affect many of the mechanical properties. It is well accepted that the grain boundary interfaces control the strength and ductility of nanostructured metals. While atomistic simulations have been widely used to study the deformation mechanisms associated with the grain boundary atomic structure, such simulations often focus on highly idealized, minimum energy grain boundary states. In reality, global equilibrium is rarely achieved in materials and often results in higher energy metastable grain boundary states. In addition, grain boundaries also tend to develop faceted hill and valley morphologies, causing secondary dislocations to localize at the faceted junctions. The segregation of impurities to the grain boundaries both during processing or service can further change the character of the boundary, and affect the material’s thermal stability and mechanical behavior. Because of the presence of these defect types, strength predictions from atomistic simulations based on idealized, energy minimized grain boundary structures tend to be far off from those in actual experiments.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 14, 2022
- Source ID
- FA95501910242
Entities
People
- Huck Beng Chew
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Illinois Urbana–Champaign