Accession Number:

AD0261785

Title:

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

Descriptive Note:

Corporate Author:

FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s):

Report Date:

1961-07-27

Pagination or Media Count:

1.0

Abstract:

A method of studying equilibria in refractory nitride systems at 1500-2800 K was developed. The equilibrium in the system NrNx - 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 12 N2, was not corroborated at the pressures and temperatures investigated. As the composition of ZrNx changes, the heats and free energies of formation change considerably this must be taken into account in thermodynamic calculations. As the composition changes from ZrN0.56 to ZrN1.0, the heats of formation change from 56,100 to 87,900 calmole. The conditions of formation of zirconium nitrides of given composition were studied, and a method of synthesizing them was developed. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE