Texture Development in Polycrystalline Fe-Ga Magnetostrictive Materials
Magnetostrictive Galfenol (Fe-Ga) is a promising and mechanically robust actuator material. Single crystals of Galfenol have been shown to exhibit up to 400 ppm magnetostrictive strains with saturating fields of several hundred oersteds. However, due to the high conductivity of Galfenol, it needs to be in thin sheet form for many device applications to avoid eddy current loses. One of the main challenges in producing engineering components from these materials is shaping of these materials while retaining a preferred crystallographic texture to optimize the magnetostrictive performance of the polycrystals. In this work, the effects of rolling on texture evolution of polycrystalline Galfenol are being investigated. Results from hot rolling experiments showed that careful control of rolling conditions can minimize the formation of cracks. They also suggested that significant dynamic recovery and recrystallization occurred during the deformation process, resulting in a large number of grain orientations with very little texture. Preliminary results also showed that the specimens can be successfully warm rolled to a thickness of less than 0.5 mm.
T. Chandra, K. Tsuzaki, M. Militzer , C. Ravindran
L. M. Cheng and E. Summers, "Texture Development in Polycrystalline Fe-Ga Magnetostrictive Materials", Materials Science Forum, Vols. 539-543, pp. 3460-3465, 2007