High-silicon electrical steels containing 6.5 wt.% Si (Fe-6.5Si) are promising materials for high-efficiency electric motors because of their high electrical resistivity and low core loss. However, the intrinsic brittleness of high-silicon steels limits their formability using conventional fabrication methods, such as cold rolling, pressure forming, and sintering, making it difficult to fabricate three-dimensional (3D) soft magnetic cores for axial-flux permanent magnet (AFPM) motors. Additive manufacturing has recently attracted attention as an effective approach for producing complex magnetic components. In particular, laser powder bed fusion (LPBF) enables the fabrication of geometrically complex structures through localized melting and rapid solidification of metal powders. During LPBF, rapid thermal cycling can generate unique microstructures that influence the magnetic properties of fabricated materials. In this study, Fe-6.5Si samples were fabricated using LPBF, and their microstructure and magnetic properties were investigated. In addition, a complex-shaped 3D core was successfully fabricated by LPBF, and the performance of an AFPM motor equipped with the LPBF-fabricated core was evaluated. The results show that the LPBF-fabricated core can provide superior performance-to-weight efficiency for lightweight motor applications.

1. Introduction 
2. Experimental Procedure 
    2.1 Sample fabrication 
    2.2 Microstructure analysis and characterization 
3. Results and Discussion 
    3.1 Microstructure of the LPBF-fabricated Fe-6.5Si 
    3.2 Magnetic properties of the LPBF-fabricated Fe-6.5Si 
    3.3 Motor performance evaluation 
4. Conclusion 
Funding
Conflict of Interest 
Data Availability Statement 
Author Information and Contribution 
Acknowledgments
References

• Yeon Woo Kim(Nano Materials Division, Korea Institute of Materials Science (KIMS), Changwon 51508, Republic of Korea)
• Ji Sang Yoon(Nano Materials Division, Korea Institute of Materials Science (KIMS), Changwon 51508, Republic of Korea, Department of Metallurgical Engineering, Pukyong National University, Busan 48513, Republic of Korea)
• Jeong Min Park(Nano Materials Division, Korea Institute of Materials Science (KIMS), Changwon 51508, Republic of Korea, Center for Advanced Functional Powder, Korea Institute of Materials Science (KIMS), Changwon 51508, Republic of Korea, Department of Advanced Future Convergence Materials, Korea University (KU), Seoul 02841, Republic of Korea) Corresponding author
• Gyu Hyun Park(Center for Advanced Functional Powder, Korea Institute of Materials Science (KIMS), Changwon 51508, Republic of Korea)
• Youk Jin Kim(eP (electric propulsion) Proto Development Team, Hyundai Motor Group, Hwaseong 18280, Republic of Korea)
• Sang Heon Lee(Aerospace Development Team, Samhyun Co., Ltd, Changwon 51398, Republic of Korea)
• Jeong Seok Kim(Electrified Powertrain Development Team, Samhyun Co., Ltd, Changwon 51398, Republic of Korea)
• Sung Ho Yu(Metal 3D Printing Team, Partners Lab Co., Ltd, Changwon 51783, Republic of Korea)