Rotational Speed and Torque of Axial-Flux Motor Using Sintered Iron Nano-Polycrystalline Body

An axial-flux motor using sintered iron (Fe) nano-polycrystalline body has been developed at the first time. In this study, its mechanical properties such as rotational speed, torque, and output power properties were compared with those of axial-flux motors using soft iron cores. Experimental results showed that the maximum rotational speed of the axial-flux motor using sintered Fe nano-polycrystalline was 8000 rpm with load, double that of the axial-flux motors using a soft iron core. The torques of both types of motors were around 0.01Nm with a little difference, and the axial-flux motor using sintered Fe nano-polycrystalline had double the output power while keeping torque the same. Sintered Fe nano-polycrystalline has significantly higher magnetic permeability than common iron materials. The material has lower magnetic saturation flux density. Fe nanoparticles were produced from iron oxide particles by using high-repetition laser pulse in liquid. Core inductors with this material were fabricated. Measurements of the core inductor magnetization clarified that the specific permeability of the sintered Fe nano-polycrystalline was 1 million, much higher than the 1000-2000 of soft iron.