Phase diagram of R-Fe-Co pseudoternary system withR≤33.3 %(mole fraction, R=Sm0.5Dy0.5)
(1. School of Electrical Engineering, Hebei University of Technology,
Tianjin 300130, China;
2. Department of Materials Science and Engineering,
Shenyang Institute of Technology, Shenyang 110015, China;
3. International Center for Materials Physics, the Chinese Academy of Sciences, Shenyang 110015, China)
Tianjin 300130, China;
2. Department of Materials Science and Engineering,
Shenyang Institute of Technology, Shenyang 110015, China;
3. International Center for Materials Physics, the Chinese Academy of Sciences, Shenyang 110015, China)
Abstract: Phase equilibria of the R-Fe-Co pseudoternary system with R≤33.3%(mole fraction, R=Sm0.5Dy0.5) were determined in an isothermal section at 1073K and a vertical section of RFe2-RCo2 by using OM, X-ray diffractometer, EPMA DTA techniques. There are seven intermetallic phases: (Sm, Dy)(Fe, Co)2, (Sm, Dy)(Fe, Co)3, (Sm, Dy)6(Fe, Co)23, (Sm, Dy)2(Fe, Co)7, (Sm, Dy)(Fe, Co)5, Th2Ni17-type and Th2Zn17-type (Sm, Dy)2(Fe, Co)17. The (Sm, Dy)6(Fe, Co)23 phase dissolves 36% Co(mole fraction) at 1073K. However, the (Sm, Dy)2(Fe, Co)7 phase in R2(Fe1-xCox)7 alloys dissolves about 19% Fe(mole fraction) at 1073K.
Key words: rare earth-iron-cobalt; phase diagram; structure; compounds