Re-Determination of 1000℃ Partial Isothermal Section of the Ti-Al-Y Ternary System

The 1000℃ partial isothermal section of Ti-Al-Y ternary phase diagram has been re-determined by using diffusion couple, electron microprobe analysis and metallography. The homogeneity ranges of two temary compounds Y(Al_xTi_1-x)₂ and Y₃(Al_xTi_1-x)₂ (x=80%~100%) at 1000℃ have been discovered. Six single phase regions. nine tow phase regions and four three phase regions have been determined in the studied partial isothermal section. The max. solid solubilities of Y in TiAl and TiAl₂ were found to be 1.25%(atom) and 4.20%(atom) respectively. However, those in Ti₃Al and TiAl₃ were found to be lowrr 0.1%(atom).