Oxygen Diffusion in an Nb-Ta Alloy Measured by Mechanical Spectroscopy
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Data
2011-01-01
Autores
Grandini, Carlos Roberto [UNESP]
de Almeida, Luciano Henrique [UNESP]
Rodrigues Junior, Durval
Título da Revista
ISSN da Revista
Título de Volume
Editor
Trans Tech Publications Ltd
Resumo
When metals that present bcc crystalline structure receive the addition of interstitial atoms as oxygen, nitrogen, hydrogen and carbon, they undergo significant changes in their physical properties because they are able to dissolve great amounts of those interstitial elements, and thus form solid solutions. Niobium and most of its alloys possess a bcc crystalline structure and, because Brazil is the largest world exporter of this metal, it is fundamental to understand the interaction mechanisms between interstitial elements and niobium or its alloys. In this study, mechanical spectroscopy (internal friction) measurements were performed on Nb-8.9wt%Ta alloys containing oxygen in solid solution. The experimental results presented complex internal friction spectra. With the addition of substitutional solute, interactions between the two types of solutes (substitutional and interstitial) were observed, considering that the random distribution of the interstitial atoms was affected by the presence of substitutional atoms. Interstitial diffusion coefficients, pre-exponential factors and activation energies were calculated for oxygen in this alloy.
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Palavras-chave
diffusion, Nb-Ta Alloys, oxygen
Como citar
Diffusion In Solids and Liquids Vi, Pts 1 and 2. Stafa-zurich: Trans Tech Publications Ltd, v. 312-315, p. 1228-1232, 2011.