Effect of Ni-Content on the Transformation Temperatures in NiTi-20 at. % Zr High Temperature Shape Memory Alloys

Matthew Carl; Jesse D. Smith; Brian Van Doren; Marcus L. Young

doi:10.3390/met7110511

Metals (Nov 2017)

Effect of Ni-Content on the Transformation Temperatures in NiTi-20 at. % Zr High Temperature Shape Memory Alloys

Matthew Carl,
Jesse D. Smith,
Brian Van Doren,
Marcus L. Young

Affiliations

Matthew Carl: Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203, USA
Jesse D. Smith: Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203, USA
Brian Van Doren: ATI Specialty Alloys and Components, Albany, OR 97321, USA
Marcus L. Young: Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203, USA

DOI: https://doi.org/10.3390/met7110511
Journal volume & issue: Vol. 7, no. 11
p. 511

Abstract

Read online

The effect of Ni-content on phase transformation behavior of NiTi-20 at. % Zr high temperature shape memory alloy (HTSMA) is investigated over a small composition range, i.e., 49.8, 50.0 and 50.2 at. % Ni, by differential scanning calorimetry (DSC), high-energy synchrotron radiation X-ray diffraction (SR-XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). All samples show a monoclinic B19′ martensitic structure at room temperature. It is shown that even with these small variations in Ni-content, the alloy shows vastly different transformation temperatures and responds in a drastically different manner to aging treatments at 550 and 600 °C. Lastly, a discussion on H-phase composition with respect to bulk composition is presented.

Published in Metals

ISSN: 2075-4701 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Mining engineering. Metallurgy
Website: http://www.mdpi.com/journal/metals

About the journal

Abstract

Keywords