Magnetic properties of FeNi alloys for high-temperature thermomagnetic power generation

In this paper, the magnetic properties and heat transfer performance of Fe99.3-xNixMn0.4Si0.3 (x=33, 35, 37, 39, 41, 43) alloys near the Curie temperature (TC) were investigated. The results show that Curie temperature TC for the Fe99.3-xNixMn0.4Si0.3 alloys increases almost linearly from 450 K to 647 K with the Ni content increasing from x = 33 to x = 43. The maximum change rate of the magnetic induction (ΔB/ΔT) near the Curie temperature first increases and then decreases with the increasing Ni content. The maximum ΔB/ΔT value for Fe99.3-xNixMn0.4Si0.3 (x≥37) alloys is higher than that of the second-order phase transition materials (0.0202 T/K). Therefore, the Fe100-xNixMn0.4Si0.3 alloys are suitable for thermomagnetic power generation above 473 K. The energy conversion process of a platy sample (0.2×0.2×0.001 m3) for the alloy with x=37 in the static thermomagnetic power generation was simulated, and the maximum electromotive force of 1.47 V was generated in the simulation.