A Microstructural Investigation of the Shear Distortions and Energetics of Motions Observed in an Aged High Damping 53Cu-45Mn-2Al Alloy

Abstract

The shear distortions developed upon aging of a 53Cu-45 Mn-2Al alloy were studied using transmission electron microscope image extinctions and diffraction spot streak analysis. It was determined that a lattice distortion of (110) planes, in <111> directions developed in the alloy as aging progressed. This matured <111> shear induces a distinct V-shaped contrast which displays dynamic motion under the electron-beam irradiation of TEM examination. Video imaging techniques were applied to this activity, termed 'flickering', to investigate the energetics of the underlying crystalline lattice motion. The real-time behavior at the flicker sites suggests that the underlying mechanism which produces the dynamic contrast change is a gradual crystallographic transition, typical of a second-order phase transition. Keywords: High damping; Cu-Mn; Cu-Mn-Al; Tweed microstructure; Flickering; Image extinctions; Energetics; Chaotic activity.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1989
Accession Number
ADA208467

Entities

People

  • David M. Farkas

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Chemistry
  • Computer Programs
  • Crystal Lattices
  • Crystal Structure
  • Cubic Lattices
  • Diffraction
  • Electron Beams
  • Electron Microscopes
  • Engineering
  • Image Converters
  • Materials
  • Materials Engineering
  • Materials Science
  • Mechanical Engineering
  • Metallurgy
  • Phase Transformations
  • Physical Metallurgy

Readers

  • Image Processing and Computer Vision.
  • Thin Film Deposition Science.
  • Vision Science/Vision Psychology/Cognitive Neuroscience.

Technology Areas

  • Directed Energy
  • Directed Energy - Pulsed-Laser Deposition
  • Microelectronics