In-Situ Alloying of Fe-Si-Al Soft Magnetic Alloys Using Laser Powder Bed Fusion

Abstract

Improving efficiency and reducing power losses in electrical machines relies heavily on the development of advanced soft magnetic materials with optimized properties. To address this need, we employed in-situ alloying of 5.4% aluminum and 24.6% iron with Fe-6.5Si using the Laser Powder Bed Fusion (L-PBF) technique. This specific composition was designed to achieve a balanced set of multi-properties, including high saturation magnetization, low coercivity, high resistivity, and superior mechanical strength. The resulting Fe90.05Si4.55Al5.4 alloy was analyzed through various characterization techniques to gain insights into its microstructure, crystal structure, as well as its magnetic and mechanical properties. The analysis revealed a homogeneous alloy with a single-phase body-centered cubic (BCC) structure. Through microstructure analysis, it was found that the metal regions was dense with very few cracks whereas the elemental composition was found to be homogeneous and similar to the nominal composition in these regions. The alloy exhibited a saturation magnetization of 166 emu/g and a coercivity of 4.7 Oe and found to be magnetically stable upto a temperature of 900 K. Additionally, a Vickers hardness of 423 HV was measured, which is significantly higher than that of Fe-3.5Si and Fe-6.5Si.