Creep Behaviour of NearEquiatomic Nickel-Titanium Wires

Aysegul Akdogan Eker; Deniz Sonmez; Bedri Onur Kucukyildirim

doi:10.3139/120.110411

40% Rabatt

auf Fachbücher bei De Gruyter Brill *

Artikel

Creep Behaviour of NearEquiatomic Nickel-Titanium Wires

Aysegul Akdogan Eker , Deniz Sonmez und Bedri Onur Kucukyildirim

Veröffentlicht/Copyright: 26. Mai 2013

Veröffentlicht von

Veröffentlichen auch Sie bei De Gruyter Brill

Manuskript einreichen Informationen für Autor*innen

Aus der Zeitschrift Materials Testing Band 55 Heft 2

Abstract

The creep behaviour of near-equiatomic (50.8 at.-% Ni) NiTi wire with a diameter of 0.49 mm is studied between 82 MPa and 127 MPa tensile stress as well as in a temperature range of 575 °C to 650 °C. For 600 °C and between 82–107 MPa a stress exponent of n = 4.5 as well as for 82 MPa between 600–625 °C an activation energy of Q = 300 kJ mol^-1 have been found, these results have been compared with previous creep studies. In contrast to previous studies, this investigation has been performed with high stresses for thin NiTi wires. Moreover, fracture surfaces and ductility of wires have been investigated. The main reasons for the various results are discussed.

Kurzfassung

Das Kriechverhalten von nahezu äquiatomigen (50.8 at.-% Ni) NiTi-Drähten mit einem Durchmesser von 0,49 mm wurde zwischen Zugspannungen von 82 MPa und 127 MPa und im Temperaturbereich von 575 °C bis 650 °C untersucht. Für 600 °C und zwischen 82–107 MPa wurden ein Spannungsexponent von n = 4,5 und für 82 MPa zwischen 600–625 °C eine Aktivierungsenergie von Q = 300 kJ mol^-1 bestimmt sowie mit früheren Kriechuntersuchungen verglichen. Im Gegensatz zu früheren Studien wurden diese Untersuchungen unter hohen Belastungen der NiTi-Drähte durchgeführt. Darüber hinaus wurden die Bruchoberflächen und die Duktilität der Drähte untersucht. Die Hauptursachen für die verschiedenen Ergebnisse werden diskutiert.

Prof. Aysegul Akdogan Eker, PhD, was born in 1957, studied chemical engineering in I.D.M.M. Academy, Istanbul, Turkey, which was the older name of Yildiz Technical University. She finished her MSc at Istanbul Technical University in 1981 and PhD at Yildiz Technical University in mechanical engineering in 1987, where Akdogan Eker is working as professor. Shape memory alloys, composites, nanomaterials and corrosion topics are in her area of interest. Prof. Akdogan Eker is the Head of Mechanical Engineering Department in Yildiz Technical University, Istanbul, Turkey since 2010.

Deniz Sonmez, MSc, was born in 1980, studied mechanical engineering in Trakya University, Turkey. He finished his MSc at Yildiz Technical University in 2010. He is working in an industrial organization located in Istanbul, Turkey.

Bedri Onur Kucukyildirim, PhD, was born in 1983, studied mechanical engineering in Yildiz Technical University. He finished his MSc in 2007 and PhD in 2012 in the same department where Kucukyildirim is researcher since 2005. Composites, carbon nanotubes and corrosion are his reseach areas.

References

1 K.Nurveren, A.Akdoğan, W.M.Huang: Evolution of transformation characteristics with heating/cooling rate in NiTi shape memory alloys, J. Mater. Process Tech.196 (2008), pp. 129–134Suche in Google Scholar

2 S.M.Oppenheimer, A.R.Yung, D.C.Dunand: Power-law creep in near-equiatomic Nickel-Titanium alloys, Scripta Mater.57 (2007), pp. 377–380Suche in Google Scholar

3 M.Bram, A.Ahmad-Khanlou, A.Heckmann, B.Fuchs, H.P.Buchkremer, D.Stöver: Powder metallurgical fabrication processes for NiTi shape memory alloy parts, Mater. Sci. Eng. A337 (2002), pp. 254–263Suche in Google Scholar

4 C.Greiner, S.M.Oppenheimer, D.C.Dunand: High strength, low stiffness porous NiTi with superelastic properties, Acta Biomater.1 (2005), pp. 705–716Suche in Google Scholar

5 A.K.Mukherjee: High temperature creep mechanism of TiNi, J. Appl. Phys.39 (1968), pp. 2201–220410.1063/1.1656527Suche in Google Scholar

6 G.Eggeler, J.Khalil-Allafi, K.Neuking, A.Dlouhy: Creep of binary Ni-rich NiTi shape memory alloys and the influence of pre-creep on martensitic transformations, Int. J. Mater. Res.93 (2002), pp. 654–660Suche in Google Scholar

7 C.Lexcellent, P.Robinet, J.Bernardini, D.L.Beke, P.Olier: High temperature creep measurements in equiatomic NiTi shape memory alloy, Materialwiss. Werkst.36 (2005), pp. 509–512Suche in Google Scholar

8 E.Kobus, K.Neuking, G.Eggeler: The creep behaviour of a NiTi-alloy and the effect of creep deformation on its shape-memory properties, Pract. Metallogr.39 (2002), pp. 177–186Suche in Google Scholar

9 H.Kato, T.Yamamoto, S.Hashimoto, S.Miura: High-temperature plasticity of the β-phase in nearly-equiatomic Nickel-Titanium alloys, Mater. Trans. JIM40 (1999), pp. 343–350Suche in Google Scholar

10 EN ISO 204: Metallic Materials: Uniaxial Creep Testing in Tension – Method of Test, Beuth, Berlin (2009)Suche in Google Scholar

11 J.Brnic, G.Turkalj, M.Canadija, D.Lanc: Creep behaviour of high-strength low-alloy steel at elevated temperatures, Mater. Sci. Eng. A499 (2009), pp. 23–27Suche in Google Scholar

12 D.R.Askeland: The Creep Test, 3 rd Edition, The Science and Engineering of Materials, Chapman & Hall, Sheffield (1996)Suche in Google Scholar

13 A.K.Koul, R.Castillo, K.Willett: Creep life predictions in nickel-based superalloys, Mater. Sci. Eng.66 (1984), pp. 213–226Suche in Google Scholar

Published Online: 2013-05-26

Published in Print: 2013-02-01

Sie haben derzeit keinen Zugang zu diesem Inhalt.

Artikel in diesem Heft

https://doi.org/10.3139/120.110411