## 1 Introduction  
Research into viable alternative magnet solutions is motivated by price fluctuations and supply uncertainty of rare earth oxides and metals (e.g., Dy, Nd, and Pr), which are key components in high energy product (BH\({}_{\text{max}}\)) rare earth (RE) permanent magnets [1; 2]. Alternative permanent magnets, such as alnico, with significant improvement, provide the prospect of reduced supply instability and drastically decreased manufacturing costs for certain higher temperature applications such as traction drive motors [1; 2]. A greater variety of magnets for high temperature conditions (\(\sim\)200 \({}^{\circ}\)C) and medium energy product applications could rejuvenate RE-free magnet production and enhance production stability through removing reliance on foreign products. Alnico is a promising near-term non-RE permanent magnet because of its impressive saturation magnetization and exceptional thermal stability, featuring nearly flat magnetic property temperature dependence up to 400 \({}^{\circ}\)C [1]. Additionally, alnico presents potential for high remanence and excellent mechanical properties if powder processing improvements are successful. Next generation motor designs for automotive applications presently exist that utilize alnico magnets considering projected elevated temperature energy products [1]. Developed in the 1930s, this class of permanent magnets has intricate compositions, complex processing and byzantine heat treatments that were optimized empirically for roughly the next four decades [3; 4; 5; 6; 7; 8; 9; 10]. Due to a spinodal decomposition of the high temperature partially ordered Im\(\overline{3}\)m phase (B2-type) in alnico, a magnetic Fe-Co-rich (\(\alpha_{1}\), Pm\(\overline{3}\)m crystal structure) phase and a non-magnetic Al-Ni-rich (\(\alpha_{2}\), L\({}_{21}\) or Fm\(\overline{3}\)m crystal structure) matrix phase form during cooling [11]. Although providing the permanent magnet properties to alnico, this spinodal transformation significantly increases the processing complexity of this alloy [11; 12]. Shape anisotropy is generally considered to be the overarching mechanism for coercivity in alnico magnets, achieved after thermal annealing in a magnetic field, i.e., magnetic annealing (MA), which results in a spinodal nanoscale structure with the \(\alpha_{1}\) elongated along the applied field direction [11; 12]. To fully realize the maximum coercivity for a given MA treatment, alnico magnets are subject commonly to extended (1-20 h duration) low temperature (550-650 \({}^{\circ}\)C) annealing (\"draw\" cycles) and the combination of the MA and drawing cycles is termed full heat treatment (FHT). Recent in-depth studies of different alnico compositions have shown that very minor chemistry, processing and heat treatment changes produce distinctly different micro- and nanoscale structures, resulting in differences in remanence and coercivity, in addition to other magnetic properties [11; 13]. To produce alnico 9 magnets with the highest energy product (BH\({}_{\text{max}}\)\(\sim\) 10.5 MGOe), directionally solidified casting is required to align grains primarily along the \(<\)001\(>\) direction with considerable cost, time, and complexity [7; 11; 14]. Significant machining of these castings into final shapes removes the un-textured exterior surfaces to yield the highest energy product, but with only a coercivity of 1.5 kOe. This final machining and additional defects within these castings lead to embrittlement and breakage that requires reprocessing and large amounts of scrap material, increasing costs and material process waste [14]. Of the commercially available alnico compositions, crystallographically isotropic alnico 8H has the highest coercivity (2.02 kOe), but a relatively low energy product of 7.0 MGOe when compared to its RE alternatives [11].