TECHNOLOGYMethod of Selectively Texturing Polycrystalline Fe-Ga Alloys to the <100> Orientation
Overview
Iron/gallium (Fe-Ga) alloys are known as a magnetostrictive alloy called Galfenol. Magnetostrictive materials are broadly defined as materials that undergo a change in shape due to change in the magnetization state of the material. Nearly all ferromagnetic materials exhibit a change in shape resulting from magnetization change. The percentage of change in shape and the temperatures in which a change occurs dictate the applicatios of use for such materials.Researchers at the University of Maryland have developed GALFENOL magnetostrictive actuators and sensors have a large saturation magnetostriction potential (~400 ppm) in low applied fields (~200 Oe). It was recently reported that textured polycrystalline Fe83Ga17 exhibits magnetostrictive strain of ~170 ppm as a consequence of rolling and annealing. In order to achieve maximum performance in polycrystalline form, we examine the surface-energy-induced selective growth of {100} or {110} grains in a controlled sulfur environment during final annealing. We build on results from selective development of Goss texture in Fe-Si alloys, an a-iron alloy that is similar to Fe-Ga. Kohler suggests that although {110} growth occurs under very clean surface conditions, {100} growth occurs under slight surface contamination with sulfur due to adsorption of the sulfur.
Doped Fe-18.7 at.%Ga were successfully fabricated using a rolling process, where improves the ductility of these alloys due to suppressing grain boundary fracture and sulfur assists with formation of selective grain growth controlled by surface-energy-induced recrystallization.
For additional information please contact the Office of Technology Commercialization, University of Maryland. Phone: 301-405 3947. E-mail: [email protected]
Contact Info
UM Ventures
0134 Lee Building
7809 Regents Drive
College Park, MD 20742
Email: [email protected]
Phone: (301) 405-3947 | Fax: (301) 314-9502