Teh, W. H., Tan, L. P., Chen, S., Lee, C. J. J., Wei, F., Zhao, Y., Padhy, S. P., Chaudhary, V., Tan, C. C., & Ramanujan, R. V. (2026). Novel Fe–Ni–Si Alloys with a Balanced Property Set for Electrical Machines. Journal of Materials Research and Technology. https://doi.org/10.1016/j.jmrt.2026.05.044
Abstract:
Alloys that simultaneously exhibit good magnetic properties, high mechanical strength, and elevated electrical resistivity are critical for next-generation high-speed, high-torque electrical machines used in electric mobility and energy systems. The development of such novel alloys requires a balanced property set. However, binary Fe–Si and Fe–Ni alloys do not possess the desired combination of mechanical, magnetic and electrical properties. In earlier work, promising regions and compositions in the ternary Fe–Ni–Si system were identified via high throughput screening. Based on the results, we studied in this work a promising high-Ni–Si region (35–40 wt% Ni, 6–10 wt% Si) and a relatively low-solute composition, Fe–11.5Ni–2.7Si, using directed energy deposition and arc melting, to decouple compositional and processing effects. High Ni–Si alloys exhibited extensive intergranular intermetallic network formation, resulting in high hardness but severe embrittlement. In contrast, Fe–11.5Ni–2.7Si stabilized as a single-phase BCC matrix and exhibited an attractive combination of properties: yield strength of 551 MPa, ultimate tensile strength of 709 MPa, elongation of 4.8%, resistivity of 105 μΩ·cm, saturation magnetization of 199 emu/g and coercivity of 14 Oe. These results identify Fe–11.5Ni–2.7Si as a novel Fe–Ni–Si alloy composition that balances mechanical, electrical, and magnetic performance. These results demonstrate that intermetallic phase fraction and connectivity govern the trade-off between mechanical, magnetic, and electrical properties. Controlling phase architecture through composition and processing provides a viable design strategy for multifunctional magnetic structural alloys.
License type:
Attribution 4.0 International (CC BY 4.0)
Funding Info:
This research / project is supported by the A*STAR - Advanced Manufacturing and Engineering (AME) Programmatic Fund
Grant Reference no. : A1898b0043
This research / project is supported by the A*STAR - Advanced Manufacturing and Engineering (AME) Programmatic Fund
Grant Reference no. : A18B1b0061
This research / project is supported by the National Research Foundation - Competitive Research Programme
Grant Reference no. : NRF-CRP29 2022-0002