Effects of melt spinning speed on the microstructure of Nd_(4.5)Fe_(77)B_(18.5) alloy

The microstructure of Nd4.5Fe77B18.5 alloy melt spun at various speeds was investigated in the paper.It was found that a complex melt spun microstructure of(Nd2Fe14B+α-Fe+Fe3B) was produced with a melt spinning speed of 3 m/s,a(Nd2Fe14B+Fe3B) one with 5m/s,a microstructure composed of amorphous phase intervened with Fe3B yielded when the melt spinning speed reached 7 m/s,and a complete amorphous matter generated at a spinning speed above 20 m/s.The mechanisms by which these microstructures were formed are discussed as well.