Ultrasonic investigation of the interaction of hydrogen-dislocations in copper crystals
| Autor: | Ariel Moreno-Gobbi, G. Zamir, José Antonio Eiras |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Materials science
Condensed matter physics Hydrogen Mechanical Engineering Mineralogy chemistry.chemical_element Condensed Matter Physics Copper Crystal Condensed Matter::Materials Science Transition metal chemistry Mechanics of Materials Lattice (order) General Materials Science Ultrasonic sensor Dislocation Hydrogen embrittlement |
| Zdroj: | Materials Science and Engineering: A. 528:4255-4258 |
| ISSN: | 0921-5093 |
| DOI: | 10.1016/j.msea.2011.02.033 |
| Popis: | In this paper we present experimental data of ultrasonic velocity and attenuation obtained in a high purity crystalline sample of copper hydrogenated by gaseous charge. The sample is oriented in the 〈1 1 1〉 crystallographic direction and aged for this work in three stages between 64 and 97 days. The results indicate that the hydrogen is mainly segregated at the dislocation core, inhibiting the hydrogen Snoek–Koster relaxations verified at earlier ageing stages. Despite this, a contribution to viscosity in the kink-chain resonance is provided by the mobile hydrogen in the dislocation core by its side movement along the dislocation line. At temperatures at which the hydrogen begins to freeze in the lattice the geometrical kinks find a gradual increase on the hindering of their movements along dislocation lines, becoming immobile when the hydrogen is completely frozen in the crystal, anchoring the dislocations in short loops. Although the viscosity associated with the mobile hydrogen is removed, the resonance associated with geometrical kinks is not completely cancelled. The interaction of hydrogen-dislocation can be fully described in terms of kinks in dislocations. |
| Databáze: | OpenAIRE |
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