States of hydrogen and deuterium in chemically charged high purity aluminum

Abstract

In the present study, the deuterium distribution through the specimen thickness during charging and aging at various temperatures was characterized using the secondary ion mass spectrometry (SIMS) method. The advantages of this method are that the actual concentration–depth profiles are obtained from hydrogen (H) introduced during the growth, storage and melting environments (in single crystal or polycrystalline) of aluminum. Separately, the deuterium (D) concentration–depth profiles introduced from chemical processes or interactions with water during the experimental test processes, obtained by charging was characterized. Analysis of the pores, voids and bubbles related to hydrogen and deuterium was performed by small and wide X-ray scattering (SAXS and WAXS) and by high magnification transmission and scanning electron microscopy (TEM and SEM). Large (some micrometers in diameter) to very small (nanometers in diameter) sizes in the distribution and variability in the density of the voids/bubbles were found. The internal and surface bubbles and dense distributions of voids near dislocations related to the hydrogen distribution were studied. Moreover, the hydrogen–vacancy interactions related to microstructure changes must be taken into account in the process of characterizing the state of hydrogen in aluminum. An interpretation of the two dimensional anisotropic iso-intensities obtained by SAXS for octants voids was coded to obtain iso-intensity in the [1 1 0] plane in reciprocal space.