Influence of vanadium on hydrogen diffusion and phase constitution in Ti–H

Abstract

The nuclear magnetic resonance method is used to investigate the influence of small amounts of vanadium on the phase constitution and hydrogen diffusion in Ti‐H. The temperature dependence of the proton spin‐lattice relaxation time is obtained at 27 MHz for samples representative of the α, β and γ phases of the system. The influence of V on the Ti‐H phase diagram is presented. The probable location of hydrogen in the β phase is found to be the octahedral Oz sites of the b.c.c. lattice. It is determined that the hydrogen diffusion activation energy Ea in the β phase of Ti‐H containing about 4% V is (2.3 ± 0.1) kcal/mole which is about 1/3 of that obtained for the vanadium free case. This amount of vanadium has very little effect on the activation energy in the α phase where it is found that Ea = (11.5 ± 0.8) kcal/mole. It is also found that vanadium decreases the hydrogen diffusion activation energy in the γ phase and causes a non‐linearity in the Arrhenius plot. The lower temperature activation energies are found to be 11.2, 9.7, and 9.0 kcal/mole for TiH1.70 + 1.03% V, TiH1.74 + 2.59% V, and TiH1.63 + 4.36% V, respectively, where the vanadium percentage is the metal percentage prior to the introduction of hydrogen. The consequences of these effects on the problem of hydrogen embrittlement is discussed.

Low temperature anelasticity in Ti6Al4V alloy and Ti6Al4V–SiCf composite

“…The activation energy obtained from the peak shift (Table 1) is slightly lower than that reported for hydrogen diffusion in the ␤ phase of vanadium free titanium [6], but is slightly higher than those obtained by NMR in titanium with vanadium additions [10]. A value comparable with our results, within the uncertainty of measurements, was obtained by internal friction measurements on the Ti6Al4V alloy [11].…”

On the effect of hydrogen on the elastic moduli and acoustic loss behaviour of Ti-6Al-4V

“…estimated above and is therefore consistent with previous studies that have concluded that hydrogen occupies the octahedral interstitial sites in β titanium [45][46][47]. In addition to the position of the peak maximum, the form of the acoustic loss peak gives information about the nature of the associated process.…”

Micro-Chemistry and Mechanical Behaviour of Ti6Al4V-SiC_f Composite Produced by HIP for Aeronautical Applications

“…On the basis of the IF spectra presented above, the major peak can be attributed to hydrogen. The activation energy obtained from the peak shift is slightly lower than that reported for hydrogen diffusion in the β phase of vanadium free titanium [44], but is slightly higher than those obtained by NMR in titanium with vanadium additions [45]. A value comparable with our results, within the uncertainty of measurements, was obtained by IF measurements on the Ti6Al4V alloy [46].…”