Performance boost of co-rich fe-co based alloy magnetostrictive sensors via nitrogen treatment

• Published in: Sensors and actuators. A. Physical. Vol. 295; pp. 75 - 83
• Main Authors: Nakajima, Kenya, Kurita, Hiroki, Narita, Fumio
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15-08-2019; Elsevier BV
• Subjects: Alloys; Bending vibration; Bimetals; Cobalt; Corrosion; Corrosion fatigue; Corrosion resistance; Corrosion tests; Corrosive wear; Electric potential; Energy harvesting; Fe-Co/Ni bimetals; Ferrous alloys; Hysteresis loops; Magnetic permeability; Magnetism; Magnetostriction; Magnetostrictive effect; Mechanical properties; Nickel; Nitriding; Nitrogen treatment; Performance enhancement; Sensors; Surface properties; Voltage; Wear resistance; Magnetostrictive effect; Nitrogen treatment; Sensors; Energy harvesting; Fe-Co/Ni bimetals
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2019.05.033

The change of inverse magnetostrictive characteristics of Co-rich Fe-Co alloy bimetals was evaluated by the nitriding treatment. It was shown that the magnetostriction susceptibility of the nitrided Fe-Co/Ni alloy bimetals is larger than for the as-rolled ones. In addition, nitrided Fe-Co/Ni alloy bimetal cantilever exhibited excellent power-generating capacity.
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•The magnetostrictive characteristic of nitrided bimetals was investigated.•We obtained larger magnetostrictive susceptibility by using nitrided bimetals.•The nitrided Fe-Co/Ni bimetal indicated dramatic increase in power-generating performance.•The proposed nitriding treatment is a promising approach which contributes to the improvement of the IoT sensors.
The inverse magnetostrictive response (i.e. a change in magnetization due to an applied stress) of magnetostrictive materials, the Villari effect is widely applied for sensor applications. Mechanical properties are an important factor when applied for vibration energy and sensor applications. Surface-treatment methods are widely used for enhanced performance and serviceability of engineering components, and nitriding is one of the most versatile surface engineering method nowadays. These methods allow the fine tuning of surface quality-dependent properties such as the resistance to fatigue, wear, and corrosion. In this study, the change of inverse magnetostrictive characteristics of Co-rich Fe-Co bimetals by the nitriding treatment, for 30 min at 580 °C, was evaluated. The effect of the nitriding treatment on the inverse magnetostrictive characteristics, magnetostrictive susceptibility and magnetic hysteresis loop of Fe-Co bimetals, by an applied load, were evaluated by three-point bending tests under a magnetic field. Furthermore, the output voltage of the as-rolled Fe-Co/Ni bimetal and the nitrided Fe-Co/Ni bimetal cantilevers, under bending vibration, were compared. The nitride Fe-Co/Ni bimetal construct exhibited a high output voltage compared to the as-rolled Fe/Ni bimetal.