Accession Number : AD0664830

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

Descriptive Note : Interim technical rept. 1 Feb 67-31 Jan 68,

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

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

Report Date : 31 JAN 1968

Pagination or Media Count : 33

Abstract : Mechanical tests in compression and tension over a range of temperatures embracing the ductile-brittle transition temperature have been done on irradiated and non-irradiated molybdenum and three alloys of CbMo. Stress relaxation tests in conjunction with these have been interpreted to show that gross slip and twinning are not involved in the initiation of fracture in those brittle materials. It is also deduced that irradiation damage and alloying act in a similar manner in inhibiting slip and twinning. By use of a strain gauge bridge, it was found that no slip took place within 2 x 10 to the -4th power sec of fracture, and also that gross twinning took place entirely within 2 x 10 to the -4th power sec. (Author)

Descriptors :   (*TRANSITION METALS, MECHANICAL PROPERTIES), (*TWINNING(CRYSTALLOGRAPHY), TRANSITION METALS), PHASE STUDIES, ANNEALING, BRITTLENESS, FRACTURE(MECHANICS), DAMAGE, RADIATION EFFECTS, COLD WORKING, STRAIN HARDENING, DISLOCATIONS, GRAIN SIZE, MOLYBDENUM, NIOBIUM, MOLYBDENUM ALLOYS, NIOBIUM ALLOYS, DEFORMATION, COMPRESSIVE PROPERTIES, TENSILE PROPERTIES, DUCTILITY, RELAXATION TIME, CRYOGENICS

Subject Categories : Properties of Metals and Alloys
      Crystallography
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE