Paper Title:
Influence of Strain Ratio on Bending Fatigue Life in TiNi Shape Memory Thin Wire
  Abstract

In this study, we performed the bending fatigue test and investigated the influence of strain ratio on fatigue life in TiNi shape memory thin wire. The pulsating plane bending, alternating plane bending and rotating bending fatigue tests were carried. Additionally, we carried out the observation of the fatigue fracture surface by a scanning electron microscope. The behavior of fatigue crack was investigated. The results obtained are summarized as follows. (1) The martensitic transformation (MT) stress of the superelastic thin wire (SE-NT) is higher than that of the SMA thin wire (SME-NT) and the fatigue life of SE-NT is shorter than that of SME-NT. Maximum bending strain at the fatigue limit is the MT starting strain. (2) The low-cycle fatigue life curve in plane bending for SE-NT is expressed by a power function of maximum strain εmax and the number of cycles to failure Nf. The smaller the strain ratio for the same εmax, the shorter the fatigue life. (3) In both the rotating bending and the plane bending, fatigue cracks nucleate on the surface of the wire and one fatigue crack grows preferentially. The region in which fatigue crack propagated is fan-shaped.

  Info
Periodical
Key Engineering Materials (Volumes 340-341)
Edited by
N. Ohno and T. Uehara
Pages
1193-1198
DOI
10.4028/www.scientific.net/KEM.340-341.1193
Citation
R. Matsui, H. Tobushi, Y. Makino, "Influence of Strain Ratio on Bending Fatigue Life in TiNi Shape Memory Thin Wire", Key Engineering Materials, Vols. 340-341, pp. 1193-1198, 2007
Online since
June 2007
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Anna Kulesa, Andrzej Kurek, Tadeusz Łagoda, Henryk Achtelik, Krzysztof Kluger
Abstract:The paper presents a comparison of the fatigue life curves based on test of 15Mo3 steel under cyclic, pendulum bending and...
85