A vacuum hot-extraction method was used to monitor the out-diffusion of H from cylindrical specimens which had been pre-charged with H. At temperatures ranging from 570 to 630C, the results could be described by:

D (cm2/s) = 2.0 x 10-2 exp[-12.0(kcal/g-atom)/RT]

S.Matsuo, T.Hirata: Transactions of the National Research Institute for Metallurgy, 1969, 11[2], 88-92

 

Table 4

Diffusivity of H in Pure Al

 

Temperature (K)

D (m2/s)

446

2.3 x 10-11

453

2.9 x 10-11

459

3.7 x 10-11

467

4.3 x 10-11

469

4.9 x 10-11

483

6.8 x 10-11

494

9.5 x 10-11

503

1.3 x 10-10

517

1.7 x 10-10

523

2.2 x 10-10

531

2.9 x 10-10

535

2.9 x 10-10

540

3.2 x 10-10

549

4.0 x 10-10

560

4.7 x 10-10

579

7.2 x 10-10

583

6.8 x 10-10

592

8.7 x 10-10

613

1.2 x 10-9

619

1.3 x 10-9

624

1.6 x 10-9

647

2.0 x 10-9

655

2.9 x 10-9

681

4.3 x 10-9