Stress annealing effect on the piezomagnetic coefficient of Fe-Al-B alloys

The objective is to evaluate the potential use of these alloys as smart materials of force sensors. The study comprises two alloys with compositions (Fe0.87Al0.13)98.4B1.6 (Al13) and (Fe0.82Al0.18)98.4B1.6 (Al18). The microstructure, hysteresis loops and B vs. σ|H were analyzed before and after the SA. Regarding the force sensitivity, the SA increased the piezomagnetic coefficient d33⁎ due the introduction of an extrinsic anisotropy in both Fe-Al-B alloys. Moreover, the stress range, in which the piezomagnetic coefficient d33⁎ is linear, is higher after the SA. Concerning the single phase (Fe0.87Al0.13)98.4B1.6 alloy, the force/pressure sensitivity and the linear stress range increase up to 16.8% and 47.1%, respectively. For the two phase (Fe0.82Al0.18)98.4B1.6 alloy, the increase was a bit higher, but the curves B vs. σ are hysteretic, spoiling the use of this material as a force sensor component.

Source: Physics Letters A - December 4, 2018 Category: Physics Source Type: research