A Study of Equilibrium in a Zirconium-Nitrogen System at High Temperatures and the Dependence of the Free Energy of Formation of ZrNx on its Composition and Structure
Abstract
A method of studying equilibria in refractory nitride systems at 1500-2800 K was developed. The equilibrium in the system NrN(x) - N2 was studied in the temperature range 2000-2800 K, the pressure range 0.1-300 mmHg, and a range of change in x from 0.7 to 1.0. The dependence of the equilibrium compositions on temperature and pressure was established. The composition ZrN is a special case. The decomposition equation used in the literature, ZrN yields Zr + 1/2 N2, was not corroborated at the pressures and temperatures investigated. As the composition of ZrN(x) changes, the heats and free energies of formation change considerably; this must be taken into account in thermodynamic calculations. As the composition changes from ZrN(0.56) to ZrN(1.0), the heats of formation change from 56,100 to 87,900 cal/mole. The conditions of formation of zirconium nitrides of given composition were studied, and a method of synthesizing them was developed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 27, 1961
- Accession Number
- AD0261785
Entities
People
- B. F. Ormont
- V. S. Kutsev
- Ye. I. Smagina
Organizations
- Air Force Systems Command