U Diffusion in IV-B Elements in their HCP Phase

RODOLFO A. PÉREZ, JORGE A. GORDILLO, NICOLÁS DI LALLA

Procedia Materials Science

Elsevier

Año: 2015 vol. 8 p. 861 - 867

2211-8128

A comparative diffusion study of U in Ti and Zr in their hcp phase was performed by means of D-spectrometry in an extendedtemperature range, below half the melting point, which are the temperatures of technological interest (between 500 and 850 ºC).The present diffusion coefficient (D) values for D-Ti differs from previous work in the literature, measured in samples withhigher amount of impurities and less accurate techniques, in more than two orders of magnitude, whereas the present diffusionparameters Q = 297 kJ mol-1 and D0 = 5x10-3 m2 s-1, are close to the self-diffusion ones, which is compatible with a mechanismof diffusion assisted by vacancies. Diffusion data for U in D-Zr shows a curvature in the Arrhenius plot similar to the observedfor D-Zr self-diffusion, with D values very close to the self-diffusion ones, which also indicates an assisted by vacanciesdiffusion mechanism, as expected.