Document Type

Conference Proceeding


Smart Structures and Materials

Publication Date





Newport Beach, CA


A Ni-Mn-Ga ferromagnetic shape memory alloy was tested for strain versus applied field and strain versus stress. Field- induced strains up to 6 percent were measured with a hysteresis of about 160 kA/m. The results are compared with the predictions of modeling with a focus on hysteresis. The model is applied to the case in which the magnetic external field and external load are orthogonal to each other. It predicts the magneto-mechanical hysteresis as a function of the yield stress in a twinned martensite. Magnetization versus applied field was measured on a sample that was mechanically constrained in order to understand the magnetization behavior of the sample in the absence of twin motion. These measurements give the magnetic anisotropy and are used to estimate the demagnetization fields. The measured behavior of strain with stress at constant field is approximated by the model.


Copyright 2000 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.

Copyright Owner

SPIE—The International Society for Optical Engineering



Included in

Metallurgy Commons


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