# An Additively Manufactured Fe-3 Si Stator for a High-Performance Electrical Motor
## 1 Introduction  
Additive manufacturing (AM) is continuously evolving toward industrial maturity as several industrial sectors such as construction, energy, power electronics, automotive, aerospace, and medicine are embracing it as a new production technology with an increasing trend in market adoption rate [1, 2]. In several of these applications, AM has been a successful pathway for reducing part counts, device size, weight, and cost, as well as for improving the overall performance of machines. Fabrication of electric machines using AMis still in the early stages of research; however, the manufacturing of individual components such as permanent magnets [3; 4; 5; 6; 7; 8; 9], rotors [2; 3; 4; 5], stators [6], winding coils [7], and heat exchangers [8] via AM has been reported. There are several design constraints in the conventional state-of-the-art manufacturing of high-efficiency electrical motors and generators. Laminates are required to be thin to reduce eddy current loss, whereas extreme thickness introduces coil sets, uneven surfaces, cracks, and defects during assembly and welding. Non-magnetic insulation between laminates decreases the stacking factor and magnetic properties, such as saturation induction, which introduces performance and longevity challenges. Additionally, insulation introduces thermal energy dissipation challenges and requires an additional cooling arrangement, which is incredibly challenging to integrate into conventional manufacturing. With the growing demand for high-performance electric machines in wind turbines and electric mobility, there is a need for an alternate approach to manufacturing lightweight, high-silicon steel alloys with low eddy current loss that cannot be easily manufactured with conventional techniques. Improvements to address these manufacturing limitations of electrical machines are the subject of intense research on unconventional parts design, hybrid manufacturing, and multimaterial processing. While prior research on AM for individual parts for electric machines has already shown very encouraging results [3; 4; 5; 6; 7; 8; 9], achieving fully additively manufactured electrical machines will require overcoming several challenges, including the unconventional design of electrical cores, winding, and heat exchangers and hybrid and multimaterial processing capabilities [9; 10]. The future goal of the AM of electrical machines using a single build is to achieve low-cost, consistent batch-to-batch production capabilities with good magnetic and mechanical properties [11]. The authors have previously published reviews that provide in-depth discussions on the additive manufacturing of both soft and hard magnetic materials [10; 12]. Electrical machines employ several types of electrical steel alloys, particularly Fe-Si alloys (silicon \(\leq\)6.5 wt.%), in their framework. The optimal Si content laminate, Fe-6.5 wt.%Si, is preferred for its high resistivity, relative permeability, zero magnetostriction, and moderate saturation magnetization. However, it is highly susceptible to cracking due to its low malleability, which prevents the traditional production of high-Si-content laminates via cold rolling. There are several reports of dense parts fabrication with high-Si-content Fe-Si alloys using AM techniques, such as selective laser melting (SLM) [12; 13; 14; 15] and binder jetting [16], among others. There is a smaller amount of reported literature for the complete fabrication of electrical machines or functionally robust dense electrical machine components using three-dimensional (3D) printing. Most of these research reports are focused on switch and synchronous reluctance motors due to their easier architecture for the soft magnet's parts. [PERSON] et al. reported one of the earliest additively manufactured lightweight rotors for a permanent-magnet synchronous machine using H13 tool steel (composition: C: 0.40; Mn: 0.40; Si: 1.00; Cr: 5.25; Mo: 1.35; V: 1.00), highlighting the lack of well-characterized soft magnetic materials for electrical machines [4].