Bonding, Energetics and Mechanical Properties of Intermetallics

Abstract

In high-temperature intermetallics, dislocations play an especially important role for understanding mechanisms of their deformation and fracture behavior and anomalous mechanical response which are still far from being well understood and remain a challenge to theoretical explanation. Progress in this complex area requires understanding such key phenomena as dislocation structure and mobility, and crack blunting and propagation: while they have been characterized by mesoscopic length and energy scales, they are determined on the microscopic level by the electronic structure which has, in many cases to be carefully taken into account using abinitio techniques. The most important and challenging component of our research objectives is to bridge the gap between a microscopic quantum-mechanical description of the chemical bonding and the mesoscopic phenomena which govern the mechanical response. It is highly desirable that theory describes dislocation core structure in a compact and physically transparent form which would provide a natural link with larger length theories of dislocation motion processes (kink formation, propagation and cross-slip) as well as to study how dislocations, as typical extended defects, influence functional properties.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 2000
Accession Number
ADA391734

Entities

People

  • Arthur J. Freeman

Organizations

  • Northwestern University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Alloys
  • Band Structures
  • Computational Chemistry Methods
  • Crystal Lattices
  • Crystal Structure
  • Dislocations
  • Electronic Structure Methods
  • Eutectic Composites
  • Impurities
  • Intermetallic Compounds
  • Materials
  • Mechanical Properties
  • Scientific Research
  • Simulations
  • Solid Solutions
  • Stresses

Readers

  • Materials Science (Mechanical Engineering).
  • Materials Science and Engineering.
  • Theoretical Analysis.

Technology Areas

  • Microelectronics
  • Quantum Computing