Production of Nd–Fe–B alloys by the glass slag method

Abstract
The microstructures of the Nd–Fe–B alloy with the stoichiometric composition of Nd2Fe14B produced by the glass slag method were investigated. The Nd–Fe–B melts in the molten slag materials such as lead silicate glass, soda-lime glass, and Pyrex glass experienced a large undercooling over 160 K below solidification. When the Nd–Fe–B melts were solidified either in the molten lead silicate glass or in the molten soda-lime glass, the resultant Nd–Fe–B alloys had coarse dendrites of α-Fe phase together with grains of Nd2F14B. On the other hand, the Nd–Fe–B alloys exhibited columnar dendrite grains of Nd2Fe14B phase when the Nd–Fe–B melts were solidified in the molten Pyrex glass.