Thermodynamic Properties of High Temperature Materials.

Abstract

A careful equilibrium study of the Si-N vapor system of mass spectrometry has shown that the only important binary Si-N vapor species is the previously known Si2N. Its heat of formation is 83 plus or minus 4 Kcal/mole. No ternary Si-N-O nor Si-C-N species were found. The accepted heats of formation of Si2C(g) and SiC2(g) were confirmed as was the heat of formation of Si3(g). The vaporization behavior of Si3N4(c) was studied and found to be quite complex. From a study of the vaporization of VF3 it was found that the primary vapor species at VF3(g) with minor, and approximately equal partial pressures of VF2(g) and VF4(g). Due to sample impurity little could be inferred from the vaporization of VF4. From these experiments and estimates of the auxiliary heats and thermal function, heats of formation were estimated. (Modified author abstract)

Document Details

Document Type
Technical Report
Publication Date
Mar 31, 1974
Accession Number
AD0780111

Entities

People

  • Gerry Piper
  • Norman D. Potter

Tags

DTIC Thesaurus Topics

  • Heat Energy
  • Heat Of Formation
  • High Temperature
  • Mass Spectrometry
  • Partial Pressure
  • Spectrometry
  • Standard Enthalpy Changes
  • Thermodynamic Properties
  • Transition Temperature
  • Vaporization
  • Vapors

Readers

  • Electrochemical Engineering/ Fuel Cell Technologies
  • Powder metallurgy of Titanium alloys.
  • Thermal Physics or Thermal Science.

Technology Areas

  • AI & ML