Nesma Aboulkhair, Technology Innovation Institute

14 July 2022 14:20 - 14:50

Additive manufacturing (AM) of functional materials is receiving growing attention at a significantly fast pace. The use of metal AM processes with magnetic materials to fabricate devices rather than components has recently seen a lot of advancements. NdFeB as a permanent magnetic material combined with the plethora of advantages that AM has to offer promises new prospects in various applications. However, it poses a lot of challenges due to its brittleness when processed by laser powder bed fusion (L-PBF).

In this work, we present an overview of the cracking phenomenon that occurs during production of these magnets and propose feasible means of mitigation. The microstructural features, their formation mechanisms and phase transformations during the characteristic layer-by-layer processing in L-PBF, were investigated. The structural integrity of the printed magnets was also evaluated. Although the crack reduction was enabled, residual cracking remained that compromised the mechanical performance of the magnets.

Therefore, we demonstrate that infiltration was successful to improve the structural integrity of the manufactured magnets. The magnetic properties were measured and correlated to the process parameters and the metallurgy of the manufactured parts. Lastly, a demonstration for using the printed magnets in a motor is presented.