One- and two-step phase transformation in Ti-rich NiTi shape memory alloy

Issue title: E-MRS Fall Meeting 2005

Article type: Research Article

Authors: Paula, A.S.^a | Mahesh, K.K.^{a; *} | dos Santos, C.M.L.^b | Canejo, J.P.H.G.^a | Fernandes, F.M. Braz^a

Affiliations: [a] CENIMAT, Campus da FCT/UNL, 2829-516 Monte de Caparica, Portugal | [b] Department of Mechanical and Material Engineering, IME, Pça Gen. Tibúrcio, 80, Urca, Rio de Janeiro, Brazil – CEP 22290-270

Correspondence: [*] Corresponding author: K.K. Mahesh, CENIMAT, Campus da FCT/UNL, 2829-516 Monte de Caparica, Portugal. Tel.: +351 21 294 85 62; Fax: +351 21 294 85 58; E-mail: [email protected]

Abstract: In the present study, the phase transformations in the Ti-rich (51.0 at% Ti–Ni) NiTi Shape Memory Alloy (SMA) was analyzed using four characterization techniques: Differential Scanning Calorimetry (DSC), Electrical Resistivity (ER), Dilatometry and X-Ray Diffraction (XRD). During the phase transformations various physical parameters of the material are modified and each technique senses different physical phenomena. In order to distinguish the different types of sequences (one-step versus two-step) the observations are discussed highlighting the capability of each technique to analyze the phase transformations in NiTi SMAs.

Keywords: Shape memory effect, transformation steps, DSC, electrical resistivity, dilatometry, XRD

DOI: 10.3233/JAE-2006-727

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 23, no. 1-2, pp. 25-32, 2006