The Alnico 8 alloy has been printed using the selective laser melting additive manufacturing approach, resulting in material with magnetic properties in the as-printed state comparable to properties produced by conventional casting or powder metallurgy routes. Microstructural characterization in 3D, via electron backscattered diffraction (EBSD) in a TriBeam microscope, simultaneously reveals a fine-scale grain structure, grain orientations and sub-grain misorientation gradients as a function of proximity to spherical pores that form during the print process. The nanostructure of the 3D printed part has the same highly coherent spinodal ${\alpha }_1//{\alpha }_2$ structure observed in conventionally fabricated Alnico 8, which gives rise to a coercivity (${\mathrm{H}}_c$) of 51.2 kA ${\text{m}}^{-1}$. Further investigation of the phase constituents by TEM analysis provides an understanding of the microstructure evolution during the additive manufacturing process. Modified processing pathways for improved microstructure and properties are discussed.

Alnico 8 合金已使用选择性激光熔化增材制造方法进行打印，从而使材料在打印状态下具有磁性，可与传统铸造或粉末冶金路线产生的性能相媲美。通过 TriBeam 显微镜中的电子背散射衍射 (EBSD) 进行 3D 微观结构表征，同时揭示了细粒度晶粒结构、晶粒取向和亚晶粒取向差梯度，作为与打印过程中形成的球形孔的接近度的函数。3D 打印部件的纳米结构具有相同的高度连贯的旋节线${\mathrm{一种}}_1//{\mathrm{一种}}_2$ 在传统制造的 Alnico 8 中观察到的结构，这会产生矫顽力（${\mathrm{H}}_C$) 51.2 kA ${\text{米}}^{-1}$. 通过 TEM 分析对相成分的进一步研究提供了对增材制造过程中微观结构演变的理解。讨论了改进的微观结构和性能的改进加工途径。