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

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)

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1964
Accession Number
AD0434108

Entities

People

  • Robert G. Lye
  • Wendell S. Williams

Tags

DTIC Thesaurus Topics

  • Band Structures
  • Coefficients
  • Energy Bands
  • High Temperature
  • Metals
  • Plastic Flow
  • Single Crystals
  • Strain Rate
  • Surface Properties
  • Titanium
  • Transition Metals

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Metallurgy
  • Structural Health Monitoring of Composite Structures.

Technology Areas

  • Microelectronics
  • Microelectronics - Graphene