Tuning the phase stability and magnetic properties of laser additively processed Fe-30at%Ni soft magnetic alloys

The widely used soft-magnetic alloy, Fe-30at%Ni, has been deposited using laser engineered net shaping (LENS™). A range of laser powers and travel speeds have been studied and correlated to phase stability and magnetic properties of the alloy. Columnar grains of the metastable fcc phase are predominant for slower travel speeds, however with increasing travel speeds, a substantial volume-fraction of a bcc, possibly martensitic, phase was observed. The bcc dominated microstructures exhibit a substantially higher saturation magnetization (Ms) compared to the fcc dominated microstructures.