The metallic glass was studied, by using electrochemical techniques, at temperatures of between 313 and 353K. The gas pressures ranged from 1 to 100kPa. It was found that a very good fit to the permeation transients could be obtained by using Fick's theory. The latter results were also in good agreement with data which were obtained by using time-lag methods. The diffusivity was independent of the input H concentration, over the concentration range which was used. The permeability was described by:
P (atomH/s m Pa½) = 2.24 x 1016 exp[-48.99(kJ/mol)/RT]
and the diffusivity (table 80) could be described by:
D (m2/s) = 8.52 x 10-7 exp[-47.07(kJ/mol)/RT]
It was found that annealing (573K, 1h) decreased both the diffusivity and the permeability.
R.W.Lin, H.H.Johnson: Journal of Non-Crystalline Solids, 1982, 51[1], 45-56
Table 80
Diffusivity of H in Fe40Ni40P14B6
Temperature (K) | Pressure (Pa) | Method | D (m2/s) |
333 | 105 | time lag | 3.36 x 10-14 |
333 | 105 | transient | 3.16 x 10-14 |
338 | 105 | time lag | 4.39 x 10-14 |
338 | 105 | transient | 4.31 x 10-14 |
343 | 105 | time lag | 5.59 x 10-14 |
343 | 105 | transient | 5.38 x 10-14 |
353 | 105 | time lag | 9.61 x 10-14 |
353 | 105 | transient | 9.57 x 10-14 |
343 | 7.5 x 104 | time lag | 5.22 x 10-14 |
343 | 7.5 x 104 | transient | 5.11 x 10-14 |
343 | 1.1 x 104 | time lag | 4.80 x 10-14 |
343 | 1.1 x 104 | transient | 4.86 x 10-14 |
343 | 4 x 103 | time lag | 5.04 x 10-14 |
343 | 4 x 103 | transient | 4.83 x 10-14 |