Enhancement of fatigue life of Ni-Ti-Fe shape memory alloys by thermal cycling

Giri, Sushi K and Krishnan, Madangopal and Ramamurty, U (2010) Enhancement of fatigue life of Ni-Ti-Fe shape memory alloys by thermal cycling. In: Materials Science and Engineering A, 528 (1). pp. 363-370.

PDF Enhancement.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy

Abstract

The effect of thermal cycling on the load-controlled tension-tension fatigue behavior of a Ni-Ti-Fe shape memory alloy (SMA) at room temperature was studied. Considerable strain accumulation was observed to occur in this alloy under both quasi-static and cyclic loading conditions. Though, in all cases, steady-state is reached within the first 50-100 cycles, the accumulated steady-state strain, epsilon(p.ss), is much smaller in thermally cycled alloy. As a result, the fatigue performance of them was found to be significantly enhanced vis-a-vis the as-solutionized alloy. Furthermore, under load-controlled conditions, the fatigue life of Ni-Ti-Fe alloys was found to be exclusively dependent on epsilon(p.ss). Observations made by profilometry and differential scanning calorimetry (DSC) indicate that the 200-500% enhancement in fatigue life of thermally cycled alloy is due to the homogeneous distribution of the accumulated fatigue strain. (C) 2010 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	Materials Science and Engineering A
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Shape memory alloy; Fatigue; Martensitic phase transformation; Plastic deformation; Thermal cycling
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	21 Dec 2010 08:32
Last Modified:	21 Dec 2010 08:32
URI:	http://eprints.iisc.ac.in/id/eprint/34554

Actions (login required)

View Item