Microstructure of peritectic Tb-Dy-Fe alloys after electromagnetic levitation melting
(1. School of Materials Science and Engineering,
Shanghai Jiaotong University, Shanghai 200030, China;
2. College of Materials Science and Engineering,
Dong Hua University, Shanghai 200051, China)
Shanghai Jiaotong University, Shanghai 200030, China;
2. College of Materials Science and Engineering,
Dong Hua University, Shanghai 200051, China)
Abstract: The electromagnetic levitation melting of the rare earth giant magnetostrictive materials Tb0.27Dy0.7Fe1.90 alloys is realized. The compound is difficult to realize levitation melting at terrestrial environment because of its high density and low electric conductivity. The microstructure of the sample near peritectic composition obtained by this process contains REFe2 matrix phase, a large amount of rod-like REFe3 phase embedded in the matrix phase, rare earth rich phase enriching around the REFe3 phase and a small amount of rare earth rich phase in the REFe2 matrix phase far from the REFe3 phase, which is significantly different from that of the sample obtained by general melting-casting process with the same composition，which contains almost complete REFe2 phase and a small amount of RE rich phase in the REFe2 matrix phase. The formation of the microstructure can be attributed to the coupled growth of the peritectic phase—REFe2 and the primary phase—REFe3 , and the subsequent eutectic reaction under this experimental condition.
Key words: electromagnetic levitation melting；Tb-Dy-Fe alloys；peritectic；coupled growth