Phase equilibria of (Gd, Er) -Ti-Si systems at high temperatures

Interactions of rare earth elements with Ti-Si system at high temperatures are of academic interests for the development of refractory lightweight structural materials. As part of the fundamental research of multicomponent Ti-Si-based alloys, solid phase equilibria of the Gd-Ti-Si ternary system at 1073 K and Er-Ti-Si ternary system at 1273 K were investigated through analysis of X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). Two isothermal sections of the phase diagram and solid solubility of each equilibrium phase have been determined. The ternary compounds i.e. ErTiSi, GdTiSi, Er2Ti3Si4 and Gd1.9Ti3Si4 have been confirmed in the present condition. Binary compound ErSi1-x has not been observed. Ti3Si was confirmed to be nonexistent at both 1073 K and 1273 K. There is no intermetallic compound present in both Gd-Ti and Er-Ti binary systems.