Ultrasonic investigation of the interaction of hydrogen-dislocations in copper crystals

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:528

Article

Moreno-Gobbi, A.¹  Zamir, G.²  Eiras, J. A.³ 

[1] Univ Republ UDELAR, Fac Ciencias, Inst Fis, Montevideo 11400, Uruguay

[2] Nucl Res Ctr Negev, Dept Phys, IL-84190 Beer Sheva, Israel

[3] Univ Fed Sao Carlos, Dept Fis, BR-13565905 Sao Carlos, Brazil

关键词: Ultrasound;    Dislocations;    Hydrogen embrittlement;    Copper;   

DOI  :  10.1016/j.msea.2011.02.033

来源: Elsevier

【 摘 要 】

In this paper we present experimental data of ultrasonic velocity a] id 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, nhibiting 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 10 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. (C) 2011 Elsevier B.V. All rights reserved.

【 授权许可】

Free