Experimental determination of U diffusion in α-Ti

Abstract

α-spectrometry was used in order to measure the diffusion of U in bulk α-Ti in the temperature range 863–1123 K (540–850 °C). A straight Arrhenius plot was found, giving diffusion parameters Q = 297 kJ/mol and D ₀ = 5 × 10⁻³m²/s, which are similar to the α-Ti self-diffusion ones, when measured in Ti samples with a similar impurity content than presently. This behaviour is compatible with the hypothesis of U diffusing via a vacancy-assisted mechanism in the α-Ti lattice and contrasts with older results in which the activation energy is almost a third the self-diffusion one, even lower than the vacancy formation energy.

Keywords:

• diffusion
• U
• Ti
• α-spectrometry
• nuclear materials

Acknowledgments

The authors want to thank Dr. Roberto Passianot for his careful reading of the manuscript. This work was partially supported by the Consejo Nacional de Investigaciones Científicas y Técnicas CONICET PIP 0804/10.