Laser powder bed fusion process optimization for the production of high-performance and efficient high-silicon steel electrical motor components

The increasing demand for high-performance electrical motor components, together with the need for improved energy efficiency and sustainability, is driving the exploration of advanced materials and manufacturing techniques. Iron-silicon alloys, especially those with high silicon content, exhibit promising electromagnetic properties but pose challenges for conventional manufacturing methods. Consequently, alternative technologies such as metal additive manufacturing, and particularly laser-based powder bed fusion of metals (PBF-LB/M), are gaining interest in the production of high-silicon steel components for electrical motors. This study focuses on optimizing the PBF-LB/M process for the production of Fe-Si6.5 components for electrical motors, addressing the challenging scenario of machines not equipped with preheatable building plates. First experiments on cubic test samples unveiled significant crack formation under different process settings, highlighting the need to refine the process parameters selection approach through the design, production and assessment of task-specific test specimens. Multiple parameter combinations were tested, leading to the identification of the two best settings in terms of porosity content. X-ray computed tomography provided additional detailed analysis of specimens fabricated under such process conditions, identifying the specific setting yielding the least internal porosity and cracks. The toroidal ferromagnetic core produced with the optimized process parameters displayed enhanced electromagnetic properties, proving the effectiveness of the proposed optimization approach. Furthermore, powder characterization revealed alterations in particle size and sphericity after fabrication, emphasizing the importance of monitoring the powder properties for achieving a sustainable yet reliable process.