Grain-boundary topological phase transitions

Abstract

We reveal the existence of a topological phase transition (Kosterlitz–Thouless type) in grain boundaries (GBs)—important internal surfaces in crystalline materials. GB dynamics are controlled by the formation/migration of line defects (disconnections) with dislocation and step character. Below the GB KT transition, disconnections of opposite signs are bound as pairs, while above it they unbind and proliferate. We demonstrate that GB KT transitions provide a fundamental understanding of many GB properties, the temporal evolution of microstructure, and how it deforms/degrades under stress.

Document Details

Document Type
Pub Defense Publication
Publication Date
Dec 14, 2020
Source ID
10.1073/pnas.2017390117

Entities

People

  • David J Srolovitz
  • Jian Han
  • Kongtao Chen

Organizations

  • Army Research Office
  • City University of Hong Kong
  • University of Pennsylvania

Tags

Fields of Study

  • Physics

Readers

  • Powder metallurgy of Titanium alloys.
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.