A MECHANISM DESCRIBING EFFECTS OF GRAIN-BOUNDARY INTERNAL FRICTION AND SMALL AMOUNTS OF INTERSTITIAL IMPURITIES ON GRAIN-BOUNDARY BRITTLENESS IN MOLYBDENUM,

Abstract

The grain boundary peak in molybdenum was measured by a torsion pendenlum, when the frequency of vibration is 1 cps, the peak occurs around 1020 degrees C. This G. B. peak is reduced by oxygen or carbon additions, but an 'alloy grain boundary peak' appears at the lower temperatures on the same damping curve. Using frequency of 1 cps, 'Oxygen peak' occurs around 890 degrees C; and 'carbon peak' occurs around 925 degrees C. Since no peak is evident on the damping vs temperature curve of molybdenum single crystals, it may be concluded that these peaks are all associated with the stress relaxation across grain boundaries. (Author)

Document Details

Document Type
Technical Report
Publication Date
Apr 03, 1969
Accession Number
AD0694823

Entities

People

  • Han Yeh-lung
  • Shu Tzu-jan
  • Wang Yeh-ning

Organizations

  • National Air and Space Intelligence Center

Tags

DTIC Thesaurus Topics

  • Boundaries
  • Brittleness
  • Crystals
  • Frequency
  • Frequency Shift
  • Friction
  • Grain Boundaries
  • Impurities
  • Internal Friction
  • Molybdenum
  • Single Crystals
  • Vibration

Fields of Study

  • Materials science

Readers

  • Acoustics.
  • Materials Science and Engineering.