Influence of annealing on enhancing soft magnetic properties in laser powder bed fusion processed Hiperco (Fe-49Co-2V)

Annealing of laser powder bed fusion (LPBF) processed Fe-49Co-2 V (Hiperco) samples at 865 degrees C for 4 h leads to a substantial improvement in its soft magnetic properties. While the as built LPBF samples exhibited relatively higher coercivities (Hc) ranging from 25.8 - 26.5 Oe, the annealed LPBF samples showed significantly lower coercivities (Hc) of 6.9 - 10.8 Oe. These lower Hc values can not only be attributed to the 15-20 times larger grain sizes, but also the higher degree of B2 ordering in the annealed condition. The enhanced degree of B2 ordering also increases the saturation magnetization (Ms), from 213 to 228 emu/g, in samples processed with a laser fluence (energy/density) of 3.4 J/mm2. These results reveal the underlying mechanisms leading to an enhancement of soft magnetic properties in LPBF processed Hiperco via annealing-induced microstructural control.