Mechanically Driven Grain Boundary Relaxation: A Mechanism for Cyclic Hardening in Nanocrystalline Ni

Abstract

Molecular dynamics simulations are used to show that cyclic mechanical loading can relax the non-equilibrium grain boundary (GB) structures of nanocrystalline metals by dissipating energy and reducing the average atomic energy of the system, leading to higher strengths. The GB processes that dominate deformation in these materials allow low-energy boundary configurations to be found through kinematically irreversible structural changes during cycling, which increases the subsequent resistance to plastic deformation.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2012
Accession Number
ADA579625

Entities

People

  • Christopher A. Schuh
  • Timothy J. Rupert

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundaries
  • Energy
  • Grain Boundaries
  • Grain Size
  • Hardening
  • Materials
  • Materials Science
  • Mechanical Properties
  • Molecular Dynamics
  • Nuclear Energy
  • Plastic Deformation
  • Prostheses And Implants
  • Resistance
  • Simulations
  • Stress Concentration
  • Tensile Strain
  • Wear Resistance

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Mechanical Engineering/Mechanics of Materials.
  • Powder metallurgy of Titanium alloys.