The diffusion of H interstitials was studied in Ti0.1Zr0.9Mn0.9V0.1Fe0.5Ni0.5, (Ti0.1Zr0.9)1.1Mn0.9V0.1Fe0.5Ni0.5 and Ti0.1Zr0.9Mn0.9V0.1Fe0.5Co0.5 alloys having the C14 structure, at 400 to 600C under H gas pressures of up to 100mbar and H concentrations of up to 0.012H atoms per metal formula unit. It was noted that the H absorption was exothermic and that the partial enthalpies of solution per H atom were −0.210 and −0.248eV for Ti0.1Zr0.9Mn0.9V0.1Fe0.5Ni0.5 and (Ti0.1Zr0.9)1.1Mn0.9V0.1Fe0.5Ni0.5. The diffusion coefficient of the H interstitials was determined from the kinetics of H-gas absorption. At 500C, the diffusion coefficients (figure 50) were about 5 x 10-5cm2/s; with activation energies of 0.292 to 0.423eV.

M.Kandavel, S.Ramaprabhu, M.Jung, H.Wipf: Journal of Alloys and Compounds, 2005, 404-406, 265-8

 

Table 304

Diffusivity of Fe in Ti60Ni40

 

Temperature (K)

D (m2/s)

602

8.3 x 10-23

611

1.4 x 10-22

619

2.5 x 10-22

632

6.4 x 10-22

653

2.6 x 10-21

665

5.6 x 10-21

676

1.1 x 10-20

688

2.0 x 10-20