On the impact of nanometric ?' precipitates on the tensile deformation of superelastic Co49Ni21Ga30

Reul, A.; Lauhoff, C.; Krooss, P.; Somsen, C.; Langenkaemper, D.; Gutmann, M. J.; Pedersen, B.; Hofmann, M.; Gan, W. M.; Kireeva, I.; Chumlyakov, Y. I.; Eggeler, G.; Niendorf, T. und Schmahl, W. W. (2022): On the impact of nanometric ?' precipitates on the tensile deformation of superelastic Co49Ni21Ga30. In: Acta Materialia, Bd. 230, 117835

Abstract

Results are presented reporting on the martensite domain variant selection and stress-induced martensite morphology in [001]-oriented superelastic Co49Ni21Ga30 shape memory alloy (SMA) single crystals under tensile load. In situ neutron diffraction, as well as in situ optical-and confocal laser scanning microscopy were conducted focusing on three differently treated samples, i.e. in the as-grown, solution-annealed and aged condition. An aging treatment performed at 350 ? promotes the precipitation of nanoprecipitates. These second phase precipitates contribute to an increase of the number of habit plane interfaces, while reducing lamellar martensite plate thickness compared to the as-grown and solution-annealed (precipitate free) samples. During tensile loading, all samples show a stress-induced formation of martensite, characterized by one single domain variant ( detwinned ) and one set of parallel habit planes in a shear band. The results clearly show that gamma' nanoprecipitates do not necessarily promote multi-variant interaction during tensile loading. Thus, reduced recoverability in Co-Ni-Ga SMAs upon aging cannot be solely attributed to this kind of interaction as has been proposed in literature so far.& nbsp;(C) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Geowissenschaften > Department für Geo- und Umweltwissenschaften
• Themengebiete: 500 Naturwissenschaften und Mathematik > 550 Geowissenschaften, Geologie
• ISSN: 1359-6454
• Sprache: Englisch