Accession Number : AD0700765

Title :   THERMODYNAMIC PROPERTIES OF TERNARY REFRACTORY CARBIDES. 1. ZIRCONIUM-NIOBIUM-CARBON.

Descriptive Note : Technical rept. 1 Jul 67-30 Jun 69,

Corporate Author : CINCINNATI UNIV OHIO

Personal Author(s) : Jun,C. K. ; Hoch,M.

Report Date : DEC 1969

Pagination or Media Count : 40

Abstract : The non-stoichiometry of zirconium-niobium-carbide with the sodium-chloride type structure, Zr(x)Nb(1-x)C(y), was studied by measuring the activities of the components as a function of composition. The samples were prepared by heating the required amounts of oxides and graphite in a high-vacuum induction furnace. Lattice parameters were measured of all specimens. At constant carbon concentration (y = constant), the lattice parameter deviates from Vegard's law at the niobium-rich end. The metal-metal interaction energy is not much different from that in the bcc metallic zirconium-niobium system. The difference between the zirconium-carbon and niobium-carbon interaction energies (E(13)-E(23)) is linearly dependent on composition. (Author)

Descriptors :   (*CARBIDES, *CRYSTAL LATTICES), SOLID SOLUTIONS, CHEMICAL BONDS, THERMODYNAMICS, ZIRCONIUM COMPOUNDS, NIOBIUM COMPOUNDS, PHASE STUDIES

Subject Categories : Physical Chemistry
      Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE