## 5 Conclusions  
Alnico magnets have been successfully produced using AM processing from pre-alloyed powders of custom compositions using both DED and EBM/PBF methods over a range of processing parameters. Alnico permanent magnet materials of both Co-lean and full-Co alloys have proven their potential for being processed by DED and are likely suitable for laser melting PBF also. Preliminary observations of DED build samples after SOQ heat treatments in both alloys showed that some uniform grain growth had occurred with some indications of texturing, probably driven by residual stresses in the post-build samples, which might be explored as a useful method of generating an aligned alnico magnet microstructure and improved magnetic properties. For AM processing by the EBM/PBF method, only the low-Co alloy was used in this study, which focused primarily on achieving acceptable pre-heat and build parameters, without any effort on optimization of the solidification morphology or texture. In fact, the major barrier to generating build samples of adequate size for magnetic treatment and characterization was identification of stable processing space for preheating of the powder bed of this magnetic material, while simultaneously avoiding \"over-sintering\" of the surrounding powder and volatilization of the lighter elements (e.g., Al). The magnetic properties of the powder also likely caused a significant deviation in beam focus compared to the calibrated position, apparently influencing energy and charge transfer into the powders. Additionally, the e-beam focus and location also were changing due to constant variation of the magnetic state of the powder bed as each new layer was spread and then preheated from the as-received condition to above the Curie temperature. This quest for a workable preheat condition finally was satisfied after developing e-beam conditions that entered the narrow preheat process window, between the solidus temperature and the lower bound of the high temperature solid solution, where a useful degree of sintering would occur. Once a stable preheating parameter set was identified, the melting parameters were able to generate a near-dense sample, which was measured at \(\sim\)99.9%. However, the high temperature required for preheating and the melting step produced an equiaxed microstructure, instead of the desired solidification texture, and resulted in volatilization of Al and Cu, significantly altering the composition. This change in composition appeared to change solidification and solid-state phase transformation behavior, including the spinodal decomposition that affected the magnetic properties. In general, the highest coercivity values for alnico AM builds were achieved by the DED samples, well above the EBM/PBF samples of similar composition. Again, the loss of Al and Cu in the EBM/PBF samples cannot be ignored as a significant factor in this coercivity loss. The highest remanence was achieved by the EBM/PBF samples at lower MA temperatures and was relatively MA time independent, but composition shifts in Al and Cu may have contributed to the higher remanence. The energy product of samples from nearly all the AM methods and alloys was lower but is likely derived from the lack of MA and FHT optimization. If the composition losses in the EBM/PBF could be addressed and if the \(<\)001\(>\) texturing could be improved for the DED and EBM/PBF methods of AM, in combination with finding the optimal MA and FHT parameters, the energy product would benefit immensely. This is especially obvious from the wide variation in magnetic properties that result from different MA times and temperatures, which control nano-structure development in the EBM/PBF samples to arrive at the ideal spacing, size and magnetic isolation of the Fe-Co rods. Additionally, solidification processing parameters for AM still need to be explored, e.g., potentially a higher thermal gradient within EBM/PBF, to achieve the ideal microstructure (columnar and textured in the \(<\)001\(>\) direction) with the highest remanence values.