Assessment of Fe–Ga–B alloy magnetomechanical behavior

The Fe–18.6% Ga alloy (at.%) has a high magnetostriction and an excellent piezomagnetic (PZM) property. However, Fe–Ga has a poor ductility and the addition of B helps to improve this property. The magnetostriction of the Fe–Ga alloy is not appreciably improved by the addition of B; however, the PZM behavior of Fe–Ga–B is unknown up to now. Then, an Fe–Ga alloy with 2% of B was produced to evaluate the effect of boron addition on the PZM property of the Fe–Ga alloy. The PZM force sensing performance coefficientd33* decreased, but the maximum sensitivity is reached for a fixed magnetic field. In addition,d33* values are among 2 and 5 mT/MPa, which is sufficient for many applications. A better ductility compared to Fe–Ga and a good sensitivity at constant field, makes the alloy Fe–Ga–B a good candidate for application as force sensors up to stresses of 80 MPa.