Effect of phase stability and composition on hydrogen diffusion in the binary systems Ti–Mo and Ti–V and related Ti-base alloys

Abstract Hydrogen diffusion coefficients D H were determined in various commercial β titanium alloys and binary titanium alloys of the Ti – Mo and Ti – V systems, since molybdenum and vanadium are the most important β-stabilizing alloying elements. For this purpose, hydrogen concentration step profiles were established in long thin titanium rod samples via electrochemical hydrogenation. Subsequent diffusion annealing at various temperatures led to hydrogen diffusion inside the samples. The hydrogen concentration profiles established were evaluated either numerically by means of a finite-difference application or analytically by applying the Matano technique and the hydrogen diffusion coefficients were calculated. The results show that the D H -values increase with increasing β stability, obey an Arrhenius-type temperature dependence and are not affected by hydrogen concentration.