Accession Number : AD0646682

Title :   TWINNING AND THE LOW TEMPERATURE MECHANICAL PROPERTIES OF POLYCRYSTALLINE COLUMBIUM, MOLYBDENUM AND CBMO ALLOYS.

Descriptive Note : Interim technical rept. 1 Feb 66-31 Jan 67,

Corporate Author : WESTINGHOUSE ELECTRIC CORP PITTSBURGH PA RESEARCH AND DEVELOPMENT CENTER

Personal Author(s) : Shaw,B. J.

Report Date : 31 JAN 1967

Pagination or Media Count : 40

Abstract : Results of the mechanical tests, in compression, tension, and by stress relaxation, on columbium, neutron-irradiated and non-irradiated molybdenum, and three CbMo alloys are discussed. The tests were made in the range 200C to -269C, which covers the ductile-brittle transition temperature of all the polycrystalline materials used. The results indicate that point defects in the crystal lattice inhibit dislocation multiplication mechanisms, thereby increasing the yield and twinning stresses and enhancing the embrittlement. Etch-pit and electron microscopy studies in columbium are described. A theoretical investigation of slip on the b.c.c. (110) and (112) planes is also given.

Descriptors :   (*NIOBIUM ALLOYS, MICROSTRUCTURE), (*MOLYBDENUM ALLOYS, MICROSTRUCTURE), TWINNING(CRYSTALLOGRAPHY), CRYSTAL DEFECTS, DAMAGE, RADIATION EFFECTS, GRAIN SIZE, CRACKS, TRANSITION TEMPERATURE, MECHANICAL PROPERTIES

Subject Categories : Properties of Metals and Alloys
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE