Alternative SmFeN permanent magnets fabricated by cold spray additive manufacturing

Neodymium/dysprosium-based permanent magnets are core components in many devices, such as electric motors, due to their unequaled magnetic performance. Considering the rapidly increasing demand and price of these rare earth elements, alternative magnet chemistries are being actively explored. SmFeN magnets are a promising replacement contender as they possess high magnetic performance while they are constituted of less critical elements. This presentation focuses on the fabrication of SmFeN permanent magnets using cold spray additive manufacturing. This approach was successfully demonstrated for the fabrication of NdFeB magnets exhibiting excellent mechanical properties. Cold spray is particularly intriguing for forming SmFeN parts as this material cannot be processed using the traditional sintering routes due to phase instability at temperatures exceeding 500°C. The relationship between the feedstock composition (binder content and size), spray parameters (temperature, pressure), microstructure and the magnetic properties (remanence, coercivity) was explored and will be discussed.