The permeation of H through a tubular membrane of the material was measured, at 257 to 323K, by using gaseous and electrolytic charging and discharging. Permeation through membranes with an appreciable H content exhibited non-local non-Fickian behavior (stress-induced diffusion). In the case of a H-free membrane, the diffusion coefficient was determined by using the breakthrough method. The diffusivity results (figure 34) could be described by the expression:

D (m2/s) = 1.1 4 x 10-7 exp[-22.2(kJ/mol)/RT]

Stress-Induced Diffusion in Hydrogen Permeation through Pd81Pt19 Membranes. B.Baranowski: Journal of the Less-Common Metals, 1989, 154[2], 329-53

Figure 34

Diffusivity of H in Pd81Pt19