ON THE MICRO-MECHANISM OF SECOND-ORDER EXTENSION OF ALUMINUM IN REVERSED CYCLIC TORSION.

Abstract

Superpure aluminum specimens extended by unidirectional straining, by the second-order effect in cyclic torsion, and by a combination of the two were studied by means of X-ray diffraction optical microscopy, tensile tests and surface-contour observation. Specimens deformed by the second-order effect show a sub-grain formation and a permanent displacement on these slip planes seen on the surface. These permanent displacements in the radial direction of the specimen are in the average in quadratic relation with the torsion amplitude applied, a relation in agreement with the theory of second-order effects. It is believed that accumulation of unidirectional strain increments occurs when slip movements during inelastic strain amplitudes do not fully reverse and when the irreversible slip governed by second-order forces produces small unidirectional displacements in each half cycle. (Author)

Document Details

Document Type
Technical Report
Publication Date
May 01, 1966
Accession Number
AD0486444

Entities

People

  • Maria Ronay

Organizations

  • Columbia University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Agreements
  • Aluminum
  • Amplitude
  • Determinants (Mathematics)
  • Diffraction
  • Displacement
  • Microscopy
  • Observation
  • Unidirectional
  • X Rays
  • X-Ray Diffraction

Readers

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