Accession Number : AD0694823

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

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Wang Yeh-Ning, ; Shu Tzu-Jan, ; Han Yeh-Lung,

Report Date : 03 APR 1969

Pagination or Media Count : 25

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)

Descriptors :   (*MOLYBDENUM, BRITTLENESS), INTERNAL FRICTION, GRAIN BOUNDARIES, IMPURITIES, METALLOGRAPHY, HEAT OF ACTIVATION, DOPING, OXYGEN, CARBON, CHINA

Subject Categories : Properties of Metals and Alloys
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE