Accession Number : AD0434108


Title :   RESEARCH TO DETERMINE THE MECHANISMS CONTROLLING THE BRITTLE-DUCTILE BEHAVIOR OF REFRACTORY CUBIC CARBIDES,


Descriptive Note : Rept. for 1 Jan-31 Dec 63,


Corporate Author : UNION CARBIDE CORP PARMA OH


Personal Author(s) : Williams, Wendell S ; Lye, Robert G


Report Date : Mar 1964


Pagination or Media Count : 67


Abstract : Plastic flow at high temperatures in single crystals of the transition metal monocarbides has been studied by determining the influence of temperature, strain rate, surface condition, and carbon/metal ratio on the compressive yield stress. Yielding in the carbides is apparently controlled by lattice friction. A study of the influence of carbon vacancies on the resistivity, p, and Hall coefficient of TiC has shown that the added resistivity/atomic per cent vacancies is 16 milliohm cm and that the value of p for stoichiometric TiC is 70 = 10 milliohm cm. Literature values for magnetic susceptibility and Hall coefficient of TiC, and new measurements of its Seebeck coefficient, are discussed in terms of a plausible band structure. The possibility of a transfer of electrons from carbon to titanium atoms is suggested, and the implications of the resulting ionic character are discussed for the elastic moduli and the cohesive energy. (Author)


Descriptors :   *REFRACTORY METAL ALLOYS , *CRYSTAL STRUCTURE , CARBIDES , TITANIUM ALLOYS , NIOBIUM ALLOYS , ZIRCONIUM ALLOYS , CREEP , DEFORMATION , BRITTLENESS , TEMPERATURE , LABORATORY FURNACES , ELECTRICAL RESISTANCE , HALL EFFECT , CRYSTAL LATTICES , DUCTILITY , MAGNETIC PROPERTIES


Distribution Statement : APPROVED FOR PUBLIC RELEASE