Correlations between the process parameters, microstructure, and properties of NdFeB magnets fabricated using laser powder bed fusion

Although the laser powder bed fusion (L-PBF) has emerged as a promising approach for producing advanced NdFeB magnets for electric motors, the reliance on energy density as a sole indicator presents significant challenges in fully elucidating the relationships among process parameters, microstructure, and material properties and identifying the key process factors. Therefore, this study attempts to directly examine the correlations among these factors and determine the key process factors. Specifically, using multiple regression analysis, we assessed the impact of process parameters – laser power, scan speed, overlap ratio, and spot size – on the material properties of NdFeB magnets. Our findings suggest that the overlap ratio significantly affects density, coercivity, and remanence. Magnets with a high overlap ratio exhibited an 11.16-fold increase in Fe proportion, which led to diminished magnetic properties. These findings provide valuable insights for optimising the L-PBF process to enhance the performance of NdFeB magnets in advanced electric motor applications.