Accession Number : AD0782094

Title :   Thermodynamics of Chemical Species Important to Rocket Technology.

Descriptive Note : Final rept.,

Corporate Author : NATIONAL BUREAU OF STANDARDS WASHINGTON D C INST FOR MATERIALS RESEARCH

Personal Author(s) : Douglas,Thomas B. ; Beckett,Charles W.

Report Date : 01 JAN 1973

Pagination or Media Count : 111

Abstract : The enthalpy of high-purity molybdenum was accurately measured 273-1173K, and joined smoothly to lower-temperature (German) and higher-temperature (NBS) results to give thermodynamic functions 273-2100K. The heat capacity of a grade of Poco graphite was measured by a subsecond-duration pulse-heating technique 1500-3000K (estimated inaccuracy, 3% or less). Based largely on earlier NBS IR and Raman spectroscopy, ideal-gas thermodynamic functions for MoF5 were generated and are tabulated for 0=6000K. Three alternative classical-thermodynamic or quasi-chemical treatments are developed for deriving thermodynamic properties from vaporization data on partially associated vapors, with calculations to illustrate experimental-error propagation for one treatment. A subsecond-duration pulse-heating technique was applied to niobium metal to measure its change in normal spectral emittance and radiance temperature at and near its melting point (wavelength, 650 nm), studying dependence on solid-state roughness (0.1 to 0.95 micrometers).

Descriptors :   *Thermodynamic properties, High temperature, Measurement, Molybdenum, Niobium, Graphite, Enthalpy, Specific heat, Molybdenum compounds, Melting point, Vapors, Emittance, Radiance

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE