FATIGUE MECHANISM IN IRON AT ULTRASONIC FREQUENCY.

Abstract

A metallographic study compares the fatigue mechanism in low-carbon iron subjected on the one hand to cycles of strain at an ultrasonic frequency of 17,000 Hz and on the other to 1,700 cpm, the relative low order employed in usual engineering tests. It is found that the ultrasonic frequency can produce fatigue cracks at strain amplitudes much smaller than those which up to now have been regarded as safe at low frequency. Further, whereas small amplitudes at low frequency spread abnormal deformation primarily in grain boundaries, those at ultrasonic frequency concentrate it in a relatively few isolated slip bands thereby, it is suggested, heightening their damaging effects. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1969
Accession Number
AD0690199

Entities

People

  • W. A. Wood
  • W. P. Mason

Organizations

  • Columbia University

Tags

DTIC Thesaurus Topics

  • Amplitude
  • Boundaries
  • Frequency
  • Grain Boundaries
  • Ultrasonic Frequencies

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Powder metallurgy of Titanium alloys.
  • Structural Health Monitoring of Composite Structures.