Nondestructive 3-Dimensional X-ray Diffraction Tomography of Stress/Strain Distribution around Fatigue Cracks in Al-Li 2090.

Abstract

Sychrotron X-ray microbeams were used to characterize the three-dimensional distribution of macrotexture associated with asperity formation during fatigue crack propagation in Al-Li 2090 T8E41. Nondestructive techniques were developed, and beams formed by a 10 micrometers diameter collimator were applied. Focus was on the center portion of 12.5mm thick plates where macrotexture correlates with asperity geometry. A very distinct type of mesotexture was found: multiple adjacent grains have nearly identical orientations and form substantial volumes of near-single-crystal (NSC) material. Transitions between differently oriented NSC volumes or an NSC region and more randomly oriented grains seem to bound asperities.

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Document Details

Document Type
Technical Report
Publication Date
Oct 17, 1997
Accession Number
ADA330970

Entities

People

  • Stuart R. Stock

Organizations

  • Georgia Tech

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Crystals
  • Detectors
  • Electron Microscopes
  • Electron Microscopy
  • Engineering
  • Geometry
  • Materials
  • Materials Science
  • Microscopes
  • Microscopy
  • Radiation
  • Scanning Electron Microscopes
  • Single Crystals
  • Synchrotron Radiation
  • Three Dimensional
  • X-Ray Computed Tomography
  • X-Ray Diffraction

Fields of Study

  • Physics

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).
  • Wave Propagation and Nonlinear Chaotic Dynamics.