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

Download or read book 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 written by YE I. SMAGINA and published by . This book was released on 1961 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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. (Author).