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Conference Proceeding


Smart Structures and Materials 2003: Modeling, Signal Processing, and Control

Publication Date





San Diego, CA


Ferromagnetic shape memory martensites in the Ni-Mn-Ga system have been demonstrated to achieve a number of the criteria required for next generation actuators including the production of large theoretical strains up to 6%. The large strain originates in the rotation of twin variants and associated twin boundary motion which occurs in response to magnetic fields. The magnetic activation holds promise in actuator design because it can lead to higher bandwidths than those achieved through pure martensite-austenite phase transformation, as is the case with thermally-activated shape memory alloys. In this paper, we report on experimental measurements collected from a cylindrical Ni49.0Mn30.0Ga21.0sample alloy, driven as cast by a collinear magnetic field-stress pair. Despite the lack of a known restoring force and the fact that no "training" procedures are applied, quasi-static strains as large as 4300 micro-strain are shown. Furthermore, dynamic results in the DC-20kHz range are presented which would suggest the presence of a Delta-E effect similar to that seen in Terfenol-D but exhibiting an opposite dependence of stiffness with DC field. The potential implications of the results for the design and control of dynamic structures based on Ni-Mn-Ga are very significant.


Proc. SPIE 5049, Smart Structures and Materials 2003: Modeling, Signal Processing, and Control, 1 (July 31, 2003); doi:10.1117/12.484011

Copyright 2003 Society of Photo Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.

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Society of Photo Optical Instrumentation Engineers



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