Magnetic materials fabricated by cold spray additive manufacturing for the next generation of electric motors

Additive manufacturing is nowadays established as a sound solution to fabricate complex-shaped parts with enhanced performance as indicated by a strong industrial interest. Complex-shaped magnets are of great interest for electric motor manufacturing as they open the way for innovative solutions for higher power density and better efficiency. Cold spray additive manufacturing allows the fabrication of 3D configurations of permanent magnets and soft magnetic materials without the need for assembly and with better mechanical properties than what can be obtained by conventional techniques. New developments on cold spray additive manufacturing of permanent magnets and soft magnetic materials will be presented via a description and analysis of the hard and soft magnetic materials selection, the process optimization (temperature, feedstock properties, magnetic loading) and the fundamental characterization results of magnetic properties (remanence and coercive field) and mechanical properties (adhesion, tensile). Improvement of electric motor design via the use of 3D shaped magnets will be illustrated through examples that were simulated using finite element analysis. Potential gains in terms of torque, torque density, torque ripple management and efficiency will be highlighted. Fabrication of relevant configurations for the automotive and aerospace industries will be illustrated via demonstrator parts realized using complex robot toolpath programming.