Effect of Heat Treatment on Magnetic Properties of Selective Laser Melting Processed INVAR Alloy

3D metal printing, or additive technology, has developed significantly in recent years. This new technology brings an entirely new form of design freedom. In the processing of magnetically soft materials, which means a significant deterioration of properties compared to conventional technologies. In principle, the selective laser melting technology causes microstructural defects that affect the mobility of the magnetic domain walls. A big challenge is also mastering the printing of heterogeneous structures that will allow the suppression of eddy currents. This article aims to point out the effect of annealing, which mitigates the impact of internal defects and improves the valuable properties of the material. The research was carried out on toroidal samples INVAR 36, i.e., binary alloy Fe-36The results document that standard annealing process increases the steepness of the magnetization curve, the loop knee is sharper, the maximum permeability increases 2.7 times. Losses are noticeably reduced if the material does not work in the saturation region.