## 4 Discussion  
The as-built and quenched conditions of the AM material both showed high levels of ductility, low magnetic saturation, and a ductile fracture mode, which were all consistent with the structure and properties typically observed in quenched wrought material. This similarity between the as-built and quenched AM materials can be rationalized due to the observed high cooling rates in the AM process, which imparted a similar microstructure compared to a quenching treatment. It can be seen in Figure 2 that all the materials tested were fully dense and the porosity commonly found in AM materials was not expected to have significantly influenced properties. It still is not clear why the fast cooling rate drove the high ductility in traditional Fe-Co-V alloys, but the two major theories are the prevention of the ordering reaction or a martensitic transformation [18]. The largest observed difference between AM and wrought materials was the grain size, which was likely coupled with the observed yield strength difference. However, repeatable grain size measurements were not easily completed with these samples for the AM condition. It has been previously shown that wrought Fe-Co alloys, such as Hiperco 50A, show a strong Hall-Petch relationship in the ordered condition [18]. Grain size measurements from this study for AM material ordered for 2 h revealed grain sizes of 5.87 \(\pm\) 0.38 \(\upmu\)m while wrought material in the same condition had grain sizes of 49.32 \(\pm\) 6.69 \(\upmu\)m. Figure 7 shows the common Hall-Petch relationship for Hiperco 50A from Sourmail [18], as well as the data from this study for both wrought and AM material aged for two hours. The wrought data clearly aligns well with the expected relationship; however, the AM data slightly overperformed the predicted strength for its grain size. While it is not clear what the specific driving force for this increased strength was, the higher oxygen content in the material, the smaller grain size, precipitate formation, and other possible non-standard microstructural features remnant from the AM process could be the cause and further work is needed to elucidate this behavior. Figure 6: Representative hysteresis loops for AM samples for various heat treatment conditions. The inset figure illustrates the differences in coercivity. In addition to the deviation from the standard Hall-Petch relationship of the ordered AM material, the ordered AM material exhibited a strong yield point behavior, while the ordered wrought material did not. As discussed by [PERSON] and [PERSON] [19], reduced grain sizes can increase the occurrence of Luders strain behavior in Fe-Co alloys. The 1-2% strain of yield point behavior for ordered AM material matches closely to reported data for Luders strain in wrought material with the same grain size, and the large grain size observed in the wrought samples has been shown to be sufficient to eliminate yield point behavior. After the initial results of ordering treatment on the AM material exhibited high coercivity and insufficient saturation in low magnetic fields, a second ordering treatment was applied to both AM and wrought materials. A summary of results is shown in Figure 8. The most-square hysteresis curve was observed in the wrought material ordered for four hours, closely followed by the four-hour ordering of the AM material and the two-hour ordering for both materials. Similar to Hall-Petch behavior for yield strength, Fe-Co alloys exhibit an inverse relationship between grain size and coercivity, though this relationship has not been effectively explored for grain sizes below 5.0 \(\upmu\)m [18]. Samples were re-evaluated for grain growth after the second ordering treatment.