Laser Powder Bed Fusion of Nd2fe14b+Nd70cu30hard Magnetic Material Using Double Exposure Scanning Strategy

Abstract

Combination of double exposure scanning strategy and low-melting Nd70Cu30 eutectic phase addition approaches was investigated to improve laser powder bed fusion of Nd2Fe14B-based hard magnetic material. Technological route of Nd2Fe14B + Nd70Cu30 powder mixture was developed to obtain initial material with proper morphology and characteristics for subsequent 3D-printing. Effect of the mentioned combination on structure of the formed material and its magnetic properties was studied. Improvement of printed material density up to 98.8 % and defectiveness reduction were shown. Three different types of areas were found in the structure of the synthesized material with variable neodymium, copper and iron content. Distribution of copper throughout the whole structure of the material showed the difference of the proposed approach with convenient grain boundary infiltration technique. More stable melting, quality of printed material and less deviations of magnetic properties were achieved due to the applied approach.

Keywords: permanent magnets, additive manufacturing, 3D-printing, laser powder bed fusion, selective laser melting, Nd2Fe14B, magnetic properties, hard magnetic materials