Phase Diagram of the Fe-rich Portion of the R-Fe-Al Pseudoternary System (R=Pr0.8Tb0.2)

Abstract

Phase equilibria in the Fe-rich portion of the R-Fe-Al pseudoternary systems (R = Pr 0.8 Tb 0.2 ) with Al ≤ 66.67 at. % and R ≤ 33.33 at. % were determined in two isothermal sections at 1000°C and 600°C by using optical microscopy, differential thermal analysis, X-ray diffraction and electron probe microanalysis techniques. The stability and homogeneity range of the intermetallic phases of Pr-Fe-Al system are practically unaffected by substitution of Tb for Pr up to 20 at. %, however, the homogeneity region of the Th 2 Zn 17 -type phase (Pr, Tb) 2 (Fe, Al) 17 is decreased to 40 at. % Al.