Magnetostrictive Fe–Ga alloy strips with a preferred orientation for lamination actuators


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Fe–Ga alloys (Galfenol) are attractive for use in magnetostrictive actuators and sensors. We investigate attributes of thin strips of rolled sheet Galfenol containing NbC particles and demonstrate their suitability for incorporation in the construction of laminated actuator devices. Most quenched samples after annealing showed high magnetostriction and good flatness. A maximum value of 183 ppm was obtained in samples annealed at 1250 °C for 2 h in rolled (Fe0.81Ga0.19)99(NbC)1 alloy.

We examine the magnetostriction response of a second alloy, (Fe0.81Ga0.19)99.5(NbC)0.5, and find it is relatively flat over a range of annealing temperature and time, and has a peak value of 132 ppm. We also assess the dynamic response of a 51-mm-long laminated rod of the (Fe0.81Ga0.19)99.5(NbC)0.5 quenched sheets. It exhibited reduced impedance roll-off with increasing frequency relative to that of a solid Galfenol rod and produced fairly constant dynamic strains up to 200 Hz, while strain in the solid rod rolled off at ∼20 Hz.