Relationship between grain orientation and magnetostrictive properties of Tb-Dy-Fe alloy

The giant magnetostrictive materials of Tb-Dy-Fe alloy can realize efficient conversion of energy and information between electromagnetic energy and mechanical energy and have been used in magnetomechnical transducers, actuators, adaptive viberation control systems, and so on. As the Tb-Dy-Fe alloy has MgCu₂ structure type, the magnetostriction along the magnetic easy axis <;111> is 16.6 times larger than that along <;100> direction. But the preparation of single crystals with <;111> orientation is difficult and cannot achieve massive production. In order to meet with the requirements in engineering, <;112> and <;110> oriented polycrystals have been prepared by various unidirectional solidification techniques. The preferred orientation is often identified by X-ray differaction(XRD) of the transverse section of directionally solidified rod. However, the XRD results are based on the diffraction of many grains and can not reflect the orientation of different grain. In this paper, electronic backscatter diffraction (EBSD) technique has been used to find out the grain orientation and the effect of different crystal orientations to magnetostriction is analyzed.