Cu. Maier et H. Kronmuller, DIFFUSION AND RELAXATION PROCESSES OF HYDROGEN IN HETEROGENEOUS MICROCRYSTALLINE FE-ZR ALLOYS, Zeitschrift fur Metallkunde, 84(6), 1993, pp. 410-418
Microcrystalline heterogeneous Fe - Zr alloys with average grain sizes
of 200 nm and 1.5 mum were produced by isothermal crystallization tre
atments from amorphous Fe90Zr10. The influence of these heterogeneous
microstructures on the local relaxation processes of hydrogen (H) was
investigated by means of magnetic after-effect (MAE) measurements in a
temperature range between 4.2 K and 475 K. The MAE spectra could be d
ivided into two diffusion regions: one where the MAE spectra could ass
igned to H reorientation processes within the phase and grain boundari
es and one where the H diffusion is determined by the crystallized pha
ses of the micrometer-sized polycrystalline alloy. The H degassing kin
etics measured by a manometric method allows a detailed correlation to
the annealing behaviour between the H relaxation spectra and the long
-range H diffusion. Considering these results with measurements of H i
n homogeneous atomic structures the annealing behaviour of the H-induc
ed MAE maxima as well as the long-range H diffusion processes could be
described by a potential model taking into account the heterogeneous
structures.