Fabrication of permalloy with superior magnetic properties using pulsed arc plasma additive manufacturing

Permalloy presents excellent soft magnetic properties, but the parts with complex shapes or large volumes cannot be prepared by traditional methods such as casting and sintering due to the generation of cracks, pores, and other defects caused by high heat input. Here, the pulsed arc plasma wire arc additive manufacturing was used to prepare permalloy, which not only can flexibly prepare defect-free samples but also can make the sample saturation magnetic induction intensity of 138.2–139.4 emu/g. The coercivity is 4.53–4.99 Oe, which is lower than the laser additively manufactured one. According to 3D characterization result, the superior magnetic properties of the AMed sample are caused by the large grain size (100 μm) and significant grain texture strength (19.65). Due to the influence of heat flow direction, the internal stress inside the sample is not uniform, and the existence of subgrain boundaries and dislocations leads to the domain wall movement being blocked and magnetic properties not reaching the best value.