Influence of interstitials elements (O, C, N) on the plastic behavior in tensile stress of polycrystalline niobium between -2530C and 8500C
Description
The fundamental mechanism of plastic deformation of polycrystalline niobium was studied with 4 samples of different purity. At low temperatures (-2530C, +250C) there is a linear relationship between the activation energy and the temperature for the four samples. The two models of Peierls-Nabarro and Escaig-Hirsh used are complementary. Ductile-brittle transition result of a competition between relaxation by fast propagation of a defect or by local plastic deformation. At intermediate temperatures (250C - 8500C) on the contrary interstitial impurities play an important role in the plastic behavior of niobium. Mechanical characteristics temperature are modified by aging and can lead to a Portevin-Le Chatelier effect if dislocations are saturated by impurities
Availability note (English)
MF available from INIS under the Report Number.Abstract (French)
On a etudie le mecanisme fondamental du comportement plastique du niobium polycristallin a l'aide de 4 nuances de purete tres differentes. A basse temperature (-2530C, +250C), on a une relation lineaire entre l'energie d'activation et la temperature quelle que soit la purete du metal. Les 2 modeles utilises de Peierls-Nabarro et d'Escaig-Hirsh sont complementaires. La transition ductile-fragile resulte d'une competition entre la relaxation par propagation brutale du defaut et par deformation plastique locale. Aux temperatures intermediaires (250C-8500C) au contraire les impuretes interstitielles jouent un role important dans le comportement du niobium. Les caracteristiques mecaniques en fonction de la temperature sont modifiees par vieillissement et ceci peut se traduire par un effet Portevin-Le Chatelier si les impuretes sont suffisantes pour saturer les dislocationsFiles
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Additional details
Additional titles
- Original title (French)
- Influence des elements intestitiels (O, C, N) sur le comportement plastique en traction du niobium polycristallin entre -253
Publishing Information
- Imprint Pagination
- 228 p.
- Report number
- FRNC-TH--847
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 11504795
- Subject category
- S36: MATERIALS SCIENCE;
- Resource subtype / Literary indicator
- Thesis
- Descriptors DEI
- AGING; BRITTLENESS; DEFORMATION; DISLOCATIONS; DUCTILE-BRITTLE TRANSITIONS; DUCTILITY; IMPURITIES; INTERSTITIALS; NIOBIUM; PLASTICITY; TEMPERATURE DEPENDENCE; TENSILE PROPERTIES
- Descriptors DEC
- CRYSTAL DEFECTS; CRYSTAL STRUCTURE; ELEMENTS; LINE DEFECTS; MECHANICAL PROPERTIES; METALS; POINT DEFECTS; TRANSITION ELEMENTS