On the effect of room temperature ageing of Ni-rich Ni–Ti alloys. (1st July 2015)

• Record Type: Journal Article
• Authors: Kustov, S.; Mas, B.; Salas, D.; Cesari, E.; Raufov, S.; Nikolaev, V.; Van Humbeeck, J.
• Is Part Of: Scripta materialia. Volume 103(2015)
• Page Start: 10
• Page End: 13
• Publication Date: 2015-07-01
• Subjects: Shape memory alloy -- NiTi -- Ageing -- Vacancies -- Precipitates; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2015.02.025
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract : We show that the cubic–monoclinic martensitic transformation (B2-B19′) in Ni-rich Ni–Ti alloys is strongly affected by room temperature exposure after quenching from 1270 K, presumably due to the initial stage of precipitation: transformation temperatures strongly decrease, the hysteresis increases and in the Ni50.8 Ti49.2 alloy the transformation gets arrested. The suppression of the B2–B19′ transformation is not preceded by the cubic–trigonal (R-phase) transition, indicating that nm-size precipitates or their nuclei do not serve as nucleation sites for the R-phase.