THE THERMAL DECOMPOSITION OF URANIUM MONOCARBIDE

Technical Report · Mon Jan 15 04:00:00 EST 1962

OSTI ID:4748803

Vozzella, P A; Miller, A D; DeCrescente, M A

The thermal stability of UC was investigated using a modified Langmuir vapor pressure technique. Uranium monocarbide vaporized congruentiy over the range 2010 to 2230 deg C. At 2175 deg C, the congruently vaporizing composition was UC/sub 1.1/. The dominant mode of vaporization in the temperature range studied was UC/sub 1.1. yields U(g) + 1.1 C(g). The vaporization rate in a high vacuum environment ranged from 2.0 x 10/sup -6/ g/cm/sup 2/-sec at 2010 deg C to 38.3 x 10/sup -6/ g/cm/sup sec at 2230 deg C. The pressure of U over UC varied approximates linearly from 1.3 x 10/sup -7/ atm at 2010 deg C to 26 x 10/ sup -7/ atm at 2230 deg C, while the carbon pressure varied from 0.3 x 10/sup -7/ to 6.4 x 10/sup -7/ over the same range. The free energy change for vaporization in the range 2010 to 2230 deg C may be expressed as DELTA F = 306,000 -- 65T ( plus or minus 35 Kcal/gfw). The heat of vaporization of UC at 298 deg K is 324.6 plus or minus 2 Kcal/gfw. The standard heat of formation of UC/sub 1.1/ at 298 deg K is --19.4 plus or minus 2.0 Kcal/gfw. (auth)

• Research Organization: Pratt and Whitney Aircraft Div., United Aircraft Corp. Connecticut Aircraft Nuclear Engine Lab., Middletown
• DOE Contract Number: AT(30-1)-2789
• NSA Number: NSA-17-015955
• OSTI ID: 4748803
• Report Number(s): PWAC-378
• Country of Publication: United States
• Language: English

Related Subjects

CARBON
CHEMISTRY
DECOMPOSITION
ENTHALPY
EQUATIONS
EVAPORATION
EVAPORATION HEAT
FORMATION HEAT
FREE ENERGY
HEATING
HIGH TEMPERATURE
NUMERICALS
PRESSURE
REACTION KINETICS
STABILITY
TEMPERATURE
THERMODYNAMICS
URANIUM CARBIDES
VACUUM
VAPORS