The 773 K isothermal section of the ternary phase diagram of the Nb–Ti–Si system

The isothermal section of the Nb–Ti–Si ternary system at 773 K has been investigated over the whole concentration range mainly by powder X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive analysis (EDX). This isothermal section consists of 10 single-phase regions, 17 two-phase regions, and 8 three-phase regions. The existence of the Ti3Si, Ti5Si3, Ti5Si4, TiSi, TiSi2, Nb5Si3, NbSi2 binary compounds at 773 K is confirmed. No new ternary compound is found, but six ternary solid solutions were found. The solubilities of Nb in TiSi2, TiSi, Ti5Si4, Ti5Si3 and Ti3Si were determined to be up to 21, 8, 12, 23 and 12 at.% Nb, respectively; the solubility of Ti in Nb5Si3 is about 20 at.% Ti.