Anomalies in Measurement of Residual Stress by X-Ray Diffraction.

Abstract

Residual stresses are expected to lead to a linear dependence of the interplanar spacing, d, on sine squared psi (where psi is the sample tilt) and the stress can be obtained from the slope of this line. As a result of the linear dependence a two-tilt method is often employed to obtain the stress. However, when a specimen is subjected to extensive plastic deformation large deviations from a straight line can occur and a two-point method can lead to an erroneous stress determination. The results reported here show that: (1) this is more likely to occur in homogeneous materials than in multiphase materials (2) the oscillations follow closely the variation in peak intensity due to texture (3) the oscillations are caused by microstresses which are due to an 'orientation' effect as suggested by Weidemann. A simple, easy-to-use procedure has been developed and tested to correct the data and obtain the correct macrostress. The materials used were Armco iron, steel and ordered Cu3Au. (Modified author abstract)

Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1974
Accession Number
AD0783677

Entities

People

  • Jerome B. Cohen
  • R. H. Marion

Organizations

  • Northwestern University

Tags

DTIC Thesaurus Topics

  • Absorbers (Materials)
  • Abstracts
  • Advanced Materials
  • Diffraction
  • Engineered Materials
  • Intensity
  • Materials
  • Measurement
  • Oscillation
  • Plastic Deformation
  • Residual Stress
  • Residuals
  • Stresses
  • X Rays
  • X-Ray Diffraction

Readers

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

Technology Areas

  • Space