Transformation of RE2Fe17Bx (RE＝Nd, Dy) Metastable Phase Crystallized from Undercooled Melt

抄録

8Nd_2Dy_85Fe_5B droplets were containerlessly solidified using a 26m drop tube. The substitution of Dy for Nd in the 10Nd_85Fe_5B sample suppressed the formation of the a-Fe phase and promoted the crystallization of theRE2Fe17Bx metastable phase. The sample with a diameter range of 1200uM　to　1500uM　mainly　consisted of the RE2Fe17Bx metastable phase. The metastable phase was partially decomposed into the a-Fe and RE2Fe14B　phase during the postsolidification cooling stage. When the sample washeated, the metastable phase decomposed into the a-Fe and RE2Fe14B phases at around 1140K　which was 40K higher than that in the 10Nd_85Fe_5B ternary alloy. Key Words: Metastable phase, Undercooling, solidification, Nd-Fe-B magnet, Containerless processing