MATERIAL PROPERTY CORRELATIONS FOR URANIUM MONONITRIDE .1. PHYSICAL-PROPERTIES

The experimental data for the lattice parameter (a), density (p), and mean linear thermal expansion coefficient (α) of uranium mononitride (UN) have been collected and reviewed. Empirical correlations for these three properties as functions of temperature (T, in K) were developed and are given as: a( A ̊) = 4.879 + 3.264 × 10-5(T) + 6.889 × 10-9(T2), ρ(g/cm3) = 14.42-2.779 × 10-4(T)-4.897 × 10-8(T2), α(K-1) = 7.096 × 10-6 + 1.409 × 10-9(T). The lattice parameter correlation was constructed from experimental data in the range of 298 <-, T <- 2523 K. The density and thermal expansion coefficient correlations were derived from the lattice parameter correlation, and are therefore only strictly applicable over the same temperature range. However, all of the correlation forms employed are very stable; thus, application of these correlations to temperatures above 2523 K should yield reasonable estimates for these properties. © 1990.