Toward understanding the microstructure characteristics, phase selection and magnetic properties of laser additive manufactured Nd-Fe-B permanent magnets

Abstract

Highlights Nd-Fe-B permanent magnets with different solidification conditions are prepared using vacuum induction melting (VIM), laser directed energy deposition (LDED) and laser powder bed fusion (LPBF) technologies, respectively. The intrinsic relationship among the microstructure evolution, phase selection and magnetic properties of the Nd-Fe-B magnets under different solidification conditions is clarified in detail. The solidification velocity ( V ) and cooling rate ( R ) are key factors in determining the phase selection of Nd-Fe-B magnets. A coercivity of 656 kA m −1 , a remanence of 0.79 T and maximum energy product of 71.5 kJ m −3 are achieved in the LPBF Nd-Fe-B magnet.