Permanent Magnets Produced by Cold Spray Additive Manufacturing for Electric Engines

Abstract

With the global trend towards electrification of transport, the interest for various configurations of electric motors is growing. Unfortunately, the low versatility of the motor magnet fabrication technologies limits the development of new motor geometries. Cold spray additive manufacturing was used for shaping permanent magnets for the direct fabrication of electric motor parts without the need for additional assembly steps. This novel technique allows an increase in the design flexibility of electrical machine geometries targeting improved performance. The permanent magnets were deposited from a NdFeB-Al composite powder mix featuring high raw theoretical remanence and coercivity. The role of the process parameters such as powder mix composition, binder granulometry and gas temperature on the magnetic volume fraction and the resulting magnetic properties will be investigated and compared with data from the literature. The use of complex robot toolpath programming necessary to spray on motor parts will be illustrated through an example of the fabrication of a complex shape rotor. The obtained magnetic properties demonstrate the feasibility of using cold spray additive manufacturing as an effective technology to fabricate motor parts without additional assembly steps.