Effect of texture on the magnetostriction of grain-aligned composite Terfenol-D

Abstract

Grain-aligned composite Terfenol-D was fabricated via unidirectional solidification, followed by the infiltration of epoxy. The fraction of the RFe2 phase in composite Terfenol-D depends on the iron/rare earth (RE=Tb,Dy) ratio of the as-grown Terfenol-D and the direction of the RFe2 phase in the as-grown Terfenol-D changes from [110] to [111] with an increasing iron/rare earth ratio. For a series of grain-aligned composite Terfenol-D with different RFe2 fractions, the magnetostriction was found to increase from 813 to 1013 ppm with increases in the RFe2 fraction. A model for the magnetostriction of grain-aligned composite Terfenol-D was developed based on the modified uniform strain condition. The modified uniform strain model was then used to predict the magnetostriction of grain-aligned composite Terfenol-D from the fraction of the RFe2 phase, the elastic modulus for each crystal direction of the RFe2 phase obtained in a texture analysis, and the saturation magnetostriction value of each preferred direction. The predicted magnetostriction of grain-aligned composite Terfenol-D, which considers the elastic modulus with respect to the crystal direction of the magnetostrictive phase, is in agreement with the experimental results. In conclusion, in grain-aligned composite Terfenol-D fabricated using the crystal growth technique the preferred direction should be considered for predicting the magnetostriction of grain-aligned composite Terfenol-D. (c) 2006 American Institute of Physics.