Magnetomechanical performance of directionally solidified Fe–Ga alloys

Abstract

Iron-gallium alloys can produce magnetostrictions of ϳ400 ppm and might serve as mechanically robust actuator/sensing materials. However, for polycrystalline Fe-Ga alloys, the magnetostrictive performance decreases with the increasing deviations from the ideal ͗100͘ texture. In this paper, three directionally solidified Fe-Ga alloys with gallium contents of 17, 18.4, and 19.5 at. % were characterized at ambient temperature. These specimens exhibit high d 33 and magnetic permeability when subjected to applied magnetic fields, indicating their suitability for light weight actuator applications but not for high force applications due to their low saturation magnetostriction and hence low blocking force. All the alloys produce significant changes in magnetization, around 0.7M s -0.8M s when subjected to cyclic compressive stresses of 51 MPa, making them promising candidate materials for sensing and energy harvesting applications. However, eddy current effects may easily become a problem when such materials are subjected to a high frequency vibration or magnetic field due to their intrinsic high magnetic permeability.

An examination of Galfenol mechanical–magnetic coupling coefficients

“…As a magnetostrictive material, iron-gallium alloy (Galfenol, Fe 100−x Ga x with 12 < x < 30) is a particularly promising new transducer material that combines highly desirable tensile and compressive mechanical attributes with superior magnetic properties [1]. However, the behavior of the mechanical and magnetic phenomena is essentially non-linear, making it difficult to develop analytical models.…”

Modeling of the loading path dependent magnetomechanical behavior of Galfenol alloy

“…In previous study, most experiments carried out to study the magnetomechanical behavior of Galfenol were about measuring either magnetostriction under constant pre-compressive stress or stress-strain behavior under constant magnetic field. [1][2][3] However, when used as actuators and sensors, the Fe-Ga alloys always work under complicated magnetic and stress loading condition, which is different from the experimental loading condition in laboratory. So the study of magnetomechanical behavior of Galfenol alloy under complex loading condition is necessary and meaningful.…”