ULTRASONIC METHODS IN THE STUDY OF FATIGUE AND DEFORMATION IN SINGLE CRYSTALS OF ALUMINUM AND SODIUM CHLORIDE

Abstract

The use of ultrasonic methods for studying defect formation and its consequences in connection with stress cycling and deformation in aluminum and sodium chloride single crystals is the subject of this report. The observed ultrasonic changes appeared closely associated with changes in dislocation behavior. To establish this deformation experiments were used in such a way that results could be related to the behavior of the slip systems and to their orientation. Aluminum single crystals were used for these experiments. Simultaneous measurements of attenuation and velocity changes were made continuously during tensile deformation. In the very early stages of deformation, for all orientations, an increase in attenuation is observed before microscopic yield. Easy glide is served by the attenuation and velocity changes. Measurements in tension have been made for the purpose of comparing the dislocation damping and pinning effects in an ionic crystal with those in a metal. Important equipment improvements have been made for automatic recording of attenuation and velocity measurements.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1963
Accession Number
AD0403264

Entities

People

  • Akira Hikata
  • Bruce Chick
  • George P. Anderson
  • William Findley

Tags

DTIC Thesaurus Topics

  • Crystals
  • Frequency
  • Government Procurement
  • Governments
  • Ionic Crystals
  • Materials
  • Measurement
  • Mechanical Properties
  • Metals
  • Orientation (Direction)
  • Point Defects
  • Secondary Waves
  • Shear Stresses
  • Single Crystals
  • Sodium Compounds
  • Stress Strain Relations
  • Stresses

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Mechanical Engineering/Mechanics of Materials.