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 28

Diffusivity of H in Al

 

Temperature (K)

D (m2/s)

285

7.78 x 10-15

288

1.10 x 10-14

293

1.19 x 10-14

295

1.21 x 10-14

296

1.38 x 10-14

297

4.58 x 10-14

304

3.67 x 10-14

309

2.14 x 10-14

315

8.96 x 10-14

328

1.73 x 10-13