Experimental investigation of the Y-Fe-Ga ternary phase diagram: Phase equilibria and new isothermal section at 800 °C

The solid state phase equilibria in the Y-Fe-Ga ternary system at 800 °C were investigated by means of X-ray diffraction, scanning electron microscope (SEM) and quantitative electron probe microanalysis (EDS). The isothermal section of the Y-Fe-Ga ternary phase diagram contains 15 single phase-regions, 32 two phase-regions, 12 three phase-regions and one liquid area. The phase diagram at this temperature is characterized by the formation of ten binary stable phases. Among these, there are six extensions of the binary compounds Y2Fe17, YFe3, YFe2, YGa2, Y3Ga5 and Y5Ga3 into the ternary system Y2Fe17−x Gax (x≤2), YFe3−xGax (x≤0.8), YFe2−xGax (x≤0.14), YGa2−xFex (x≤0.5), Y3Ga5−xFex (x≤0.15) and Y5Ga3−xFex (x≤0.1), respectively. The homogeneity range of the YFe12−xGax ternary line compound is between (1.5≤x≤9.75).