Microstructure changes during non-conventional heat treatment of thin Ni–Ti wires by pulsed electric current studied by transmissionelectron microscopy

0354464 - FZÚ 2011 RIV GB eng J - Článek v odborném periodiku
Delville, R. - Malard, B. - Pilch, Jan - Šittner, Petr - Schryvers, D.
Microstructure changes during non-conventional heat treatment of thin Ni–Ti wires by pulsed electric current studied by transmissionelectron microscopy.
Acta Materialia. Roč. 58, č. 13 (2010), s. 4503-4513. ISSN 1359-6454. E-ISSN 1873-2453
Grant CEP: GA AV ČR(CZ) IAA200100627
GRANT EU: European Commission(XE) 19945 - UPWIND
Výzkumný záměr: CEZ:AV0Z10100520
Klíčová slova: TEM * heat treatment * SMA * martensitic transformation
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
Impakt faktor: 3.781, rok: 2010
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TW8-506S6KD-2&_user=625012&_coverDate=08%2F31%2F2010&_rdoc=1&_fmt=high&_orig=search&_sort=d

Transmission electron microscopy, electrical resistivity measurements and mechanical testing were employed to investigate the evolution of microstructure and functional superelastic properties of 0.1 mm diameter as-drawn Ni–Ti wires subjected to a non-conventional heat treatment by controlled electric pulse currents. This method enables a better control of the recovery and recrystallization processes taking place during the heat treatment and accordingly a better control on the final microstructure. Using a stepwise approach of millisecond pulse annealing, it is shown how the microstructure evolves from a severely deformed state with no functional properties to an optimal nanograined microstructure (20–50 nm) that is partially recovered through polygonization and partially recrystallized and that has the best functional properties.
Trvalý link: http://hdl.handle.net/11104/0193460