Enhancement of Inverse Magnetostrictive Effect through Stress Concentration for a Notch‐Introduced FeCo Alloy

Abstract

The authors investigate the magnetic flux leakage for a class of magnetostrictive FeCo alloys with a notch undergoing compression and impact with respect to energy harvesting. The magnetic flux leakage plays a crucial role in the practical energy transition in terms of the features for energy harvesting. Therefore, the corresponding situations are systematically studied by combining finite element analysis (FEA) with practical experiments. The FeCo alloys are categorized into three groups with different three-dimensional notch shapes, and the depths of the notches are 0, 0.5, and 1 mm, respectively. The parameters in both the simulations and practical tests are completely consistent. The results of compression test carried out with a stepwiseincreasing stress from 0 to 100 MPa reveal that the variations of magnetic induced flux increase with the increasing depth of the notches. The following FEA herein provides a feasible interpretation that the stress concentration around the notch is largely responsible for the notch-induced enhancement. The findings of the impacting experiments simultaneously exhibit an analogous tendency that the output power is proportional to the depth of notch. Furthermore, the stress rate has no obvious effect on the output electricity. The maximum magnitude of the improvement for the output power increases by almost 400% comparing the specimens with notches of 0 and 1 mm. This study indicates a promising feasibility to achieve vibrationenergy harvesting from various irregular components.

Twisting and Reverse Magnetic Field Effects on Energy Conversion of Magnetostrictive Wire Metal Matrix Composites

“…The final FeCo/AlSi composite was processed into a cylinder with a diameter of 10 mm and a length of 40 mm. According to several previous studies, [ 20,24,27 ] a specific shape for magnetostrictive materials has the benefits to enhance the efficiency of energy conversion. Therefore, it should be noted here that the used FeCo wires are not the straight but twisted shape, as shown in Figure a.…”

“…In contrast, certain appropriate structural design can obtain relatively great magnetostrictive properties or energy‐harvesting performance, even using common materials. It has been reported [ 20 ] that localized stress concentration introduced by a notch‐like structure has the benefits of amplifying the energy conversion or magnetostrictive properties. In addition, a multilayered composite involving positive and negative magnetostrictive materials can enhance the magnetostrictive properties for each other.…”

“…The 3D constitutive equations and the relevant properties of FeCo alloy associated with the calculation for FEA can be found in ref. [20].…”

A Review of Piezoelectric and Magnetostrictive Biosensor Materials for Detection of COVID‐19 and Other Viruses

“…Table 5 summarizes the detection limit of the Metglas sensor as applied to various targets. [113][114][115][116][117][118][119][120] Metglas 100 [97] 0.33 [98] 7.9 [97] 50.3 [99] 11 [97] Fe-Co 182 [100] 0.3 [100] 8.4 [32] 0.125 [101] 80-140 [32] CoFe 2 O 4 154 [102] 0.37 [102] 5.29 [103] −1.88 [102] −273 [104] www.advmat.de www.advancedsciencenews.com…”

“…The oscillation results in an emission of a magnetic flux, and changes in the amplitude and phase signal of the oscillation lead to a magnetic flux change that can be detected using a pick‐up coil (Figure 15b). Metglas amorphous alloy, [ 97–99 ] Fe–Co alloy, [ 32,100,101 ] and cobalt ferrite (CoFe 2 O 4 ) ceramics [ 102–104 ] are widespread materials for magnetostrictive applications. Table 4 lists the Young's modulus E , Poisson's ratio ν, mass density ρ, piezomagnetic constant , and magnetostriction λ values for these materials.…”