Additive manufacturing (AM) is a key technology for advancing many fields, including electrical machines. It offers unparalleled design freedom together with low material waste and fast prototyping, which is why it has become to focus of many researchers. For electrical machines, AM allows the production of designs with optimized mechanical, electromagnetic and thermal parameters. This paper attempts to give the reader an overview of the existing research and thermal solutions which have been realized with the use of AM. These include novel heat sink and heat exchanger designs, solutions for cooling the machine windings directly, and additively manufactured hollow windings. Some solutions such as heat pipes, which have been produced with AM but not used to cool electrical machines, are also discussed, as these are used in conventional designs and will certainly be used for additively manufactured electrical machines in the future.

In the context of rising power densities in electrical machines, additive manufacturing presents an opportunity to develop more powerful thermal solutions. However, the physical properties of objects manufactured using this process remain unclear. This research examines the directional thermal and electrical conductivities of aluminum alloy (AlSi10Mg) and silicon steel (Fe-3.7%wt. Si) samples produced via laser powder bed fusion (LPBF), both prior to and following heat treatment. The findings indicate that the as-built aluminum samples exhibit higher conductivities in the orientation parallel to the LPBF build direction, while annealing results in higher conductivities overall and an absence of anisotropy. On the other hand, the silicon steel samples show constant conductivities and lack of anisotropy both before and after heat treatment. These results have practical applications in the design of additively manufactured electrical machines, where the thermal and electrical resistance of the materials have a major impact on thermal and electromagnetic performance.

This paper presents the development of an axial flux segmented stator dual rotor switched reluctance machine, specifically designed for high-speed propulsion applications. Due to the complex three-dimensional geometry of an axial flux machines, traditional production methods face substantial limitations in manufacturing accuracy and feasibility. However, advancements in additive manufacturing have addressed these challenges by enabling the production of intricate geometries with greater precision. The paper begins with the derivation of the output power equation for the proposed machine, followed by a detailed examination of key geometric parameters influencing performance. The design methodology is outlined from initial considerations to final performance targets, with a 3D finite element method analysis conducted to validate the calculated dimensions and assess performance. Furthermore, a physical prototype is fabricated using Selective Laser Melting, an additive manufacturing technique suited for producing complex structures with high precision. The prototype undergoes experimental testing, and the resulting performance data are compared with simulated results. The comparison between FEM simulations and experimental measurements indicates a close similarity between the experimental and simulated static and dynamic torque values.

Additive manufacturing has enabled the use of advanced geometries such as lattice-structures in heatsinks. This study investigates the thermal performance of various advanced heatsink designs in the context of cooling the windings of an axial flux motor using active air cooling. Physical samples of the heatsinks are additively manufactured from an aluminum alloy and tested under realistic airflow conditions. The heatsink designs are compared against an optimized conventional finned geometry based on the measured thermal resistance at a given fan speed. This ensures that the results are representative of real-world use cases and applicable in practical solutions. The results indicate that airfoil-shaped pins can slightly outperform conventional straight fins in thermal resistance while weighing less. In terms of mass-based relative performance, the rhombi octet lattice structure outperformed the other prototypes. These findings reinforce conventional design principles in terms of absolute performance while suggesting that lattice structures can provide higher relative performance in certain weight sensitive applications.

Integrated liquid cooling jackets are widely used in the thermal management of high-power-density motors, but traditional designs rely on parametric channel layouts, failing to fully utilize the geometric degrees of freedom offered by additive manufacturing (AM). This paper proposes an AM-aware topology optimization framework based on a reduced-order cold plate model. A two-dimensional case study systematically investigates the effects of manufacturability-oriented regularization on channel topology and thermo-hydraulic performance. Results show that stronger regularization substantially reduces interface complexity and fluid area fraction, while generally increasing hydraulic resistance and degrading thermal performance. A sharp-interface reanalysis further demonstrates good agreement in the global thermal response, while revealing the sensitivity of the local peak temperature and hydraulic conductance to the density-based representation.