Microstructural Effects on Actuation Fatigue Life of Ni-rich NiTi Shape Memory Alloy Actuators
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Shape Memory Alloys (SMAs) are being used in the development of new lightweight and compact actuators for aerospace applications. One of the key challenges with the commercial implementation of SMA based actuators is the determination of functional life, because the unique material behavior conventional fatigue methods cannot be directly applied. In the present study, an experimental methodology was developed for SMAs undergoing actuation loads. Experiments were conducted to analyze the dependence of microstructure on the actuation fatigue life in Ni60Ti40 (wt. %) SMAs. The results showed a strong dependence between precipitate orientation with respect to loading direction and the actuation fatigue life. A favorable precipitate orientation can increase the life of an SMA actuator by a factor as much as six over an non-favorable orientation. Copyright © 2011 by the American Institute of Aeronautics and Astronautics, Inc.
author list (cited authors)
Calhoun, C., & Lagoudas, D.