THE ISOTHERMAL SECTION OF THE Y-Al-Sb PHASE DIAGRAM AT 800K

The isothermal section of the Y-Al-Sb ternary system at 800K has been investigated mainly by X-ray powder diffraction (XRD) with the aid of differential thermal analyses (DTA), optical microanalyses and scanning electron microscopy (SEM). It consists of 12 single-phase regions, 21 two-phase regions and 10 three-phase regions.12 single-phase regions are: a(Al), x(Sb), P (Y), 5(Y5AlxSb3.x (x=0-2.24)), e(AlSb), O(YSb), y(Y3Sb), r,(AlY3), v (A12Y3), K(A1Y), X (A12Y) and (a(A!3Y).21 two-phase regions are: a+ ? e+X' l+<^' ^ +癨 6+y, y+ P , (3 -t-rj, n.+ v , v +K, K+^, X+u., u+a, e+O, a+O, O+ii, YS^ Y3Sb, A1Y3> A12Y3^ A1Y> A\2Y, A13Y> Y5Sb3.In present work, we found that Y5AlxSb3.x (x=0-2.24) formed asingle-phase region between Y5Sb} and Y5Al(Y62 5Al28Sb95). The maximum solid solubility of Al in Y5Sb3 isabout 28at.%.No ternary compounds were found in this isothermal section.