The mutual interactions of oxygen and hydrogen in α-titanium during heat treatment

Abstract

Oxygen and hydrogen dissolve in α-phase titanium at different concentrations up to 34 at.% and 0.14 at.% respectively. Oxygen is an alphagene element while hydrogen is betagene. Firstly, the oxygen diffusion coefficient in hydrided titanium TiH 1.46 has been measured at 750 °C and additional tests have been carried out on TiH 0.2. Secondly, the hydrogen diffusion coefficient (in fact for tritium) has been determined at 400 °C in solid solutions of oxygen in titanium at 1 at.% and 2 at.%. For the case of oxygen diffusion in Ti-H, the chief effect is the disappearance of hydrides when the oxygen concentration is over 5 at.% (for TiH 0.2 by analogy with titanium) or at 2 at.% (for TiH 1.46 by direct measurement). The diffusion conditions of tritium depend greatly on the oxygen content of the metal. A value of 1–2 at.% seems to be critical; for higher oxygen concentrations, the quantity of tritium dissolved diminishes markedly. Diffusion coefficients have been measured.