Effects of Fatigue on the G. P. Zones in Al-Zn Alloys.

Abstract

Small-angle x-ray scattering has been applied to study the evolution and stability of G.P. zones in two Al-Zn alloys during fatigue, to provide statistically sound information on this process. In a 5.3 at pct Zn alloy containing zones with an average diameter of the normally sluggish coarsening was accelerated by fatigue at room temperature. In the same alloy with larger zones there is no growth, except near a fatigue crack. Reverted samples aged rapidly during fatigue at room temperature, but in a reverted sample of Al-3.5 at pct Zn tested, appreciable zone growth did not occur. Upon warming this sample (without any load) to room temperature, rapid clustering took place. These results imply a vacancy fraction produced during fatigue, and this excess vacancy concentration appears to be the cause of zone growth during room temperature fatigue.

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Document Details

Document Type
Technical Report
Publication Date
Jan 16, 1984
Accession Number
ADA137518

Entities

People

  • Jerome B. Cohen
  • R. G. Pahl Jr.

Organizations

  • Northwestern University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Atoms
  • Clustering
  • Detection
  • Detectors
  • Diagrams
  • Displacement
  • Engineered Materials
  • Failure Mode And Effect Analysis
  • Materials
  • Materials Science
  • Measurement
  • Plastic Explosives
  • Scattering
  • United States
  • Universities
  • X Ray Scattering
  • X Rays

Fields of Study

  • Materials science

Readers

  • Structural Health Monitoring of Composite Structures.
  • Thermal Physics or Thermal Science.
  • Thin Film Deposition Science.