Plastic deformation behaviour and operative slip systems in Ni3Nb single crystals

Citation
K. Hagihara et al., Plastic deformation behaviour and operative slip systems in Ni3Nb single crystals, ACT MATER, 48(7), 2000, pp. 1469-1480
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science",Metallurgy
Journal title
ACTA MATERIALIA
ISSN journal
1359-6454 → ACNP
Volume
48
Issue
7
Year of publication
2000
Pages
1469 - 1480
Database
ISI
SICI code
1359-6454(20000419)48:7<1469:PDBAOS>2.0.ZU;2-D
Abstract
Temperature and orientation dependence of yield stress and operative slip s ystem in Ni3Nb single crystals were examined. Four slip systems of (010)[10 0], (001)[100], {201}[10 (2) over bar] and (010)[001] and three twinning sy stems of {011}[0 (1) over bar 1], {211}[<(10)over bar> 7 13] and {012}[0 (2 ) over bar 1] were activated depending on the crystal orientation and teste d temperature. Anomalous strengthening was observed for some orientations w here (010)[100] or {201}[10 (2) over bar] slip was operative. A remarkable increase in the critical resolved shear stress (CRSS) for the (010)[100] sl ip occurred over a wide temperature range from -196 to 800 degrees C. The C RSS did not satisfy Schmid's law and the strain rate sensitivity of flow st ress at a small plastic strain was negligible between room temperature and 700 degrees C where an anomalous stress increase occurred. The anomalous st rengthening mechanism in Ni3Nb crystals deformed by [100] dislocations was discussed on the basis of anisotropy of APE energy on (010) and (001) in an alogy with that in Ni3Al with the L1(2) structure. (C) 2000 Acta Metallurgi ca Inc. Published by Elsevier Science Ltd. All rights reserved.