The 500℃ Lsothermal Section Of The Phase Diagram Of TI-AI-DY Ternary System

The 500℃ isothermal section of the phase diagram of Ti-Al-Dyternary system has been investigated by x-ray powder diffraction,DTA,EDAX and SEM. The phase diagram consists of 14 single-phase regions,27 two-phase regions and 14 three-phase regions.The 14 single-phase regions are: α(Ti),β(Al),γ(Dy),δ(Ti3 Al),ε(TiAl),ζ(TiAl2),η(TiAl3),ι(DyAl3),κ(DyAl2),λ(DyAl),μ(Dy3Al2),ν(Dy2Al),χ(Ti2Al20Dy),ρ(Ti4Al43Dy6),The 27 binary-phase regions are: α+δ,δ+ε,δ+ε,ε+ζ,ζ+η,η+β,β+ι,λ+μ,η+ν,ν+γ,γ+α,δ+λ,δ+ν,δ+μ,δ+κ,ε+κ,ζ+κ,η+κ,η+ι,η+ρ,χ+ρ,η+χ,χ+ι,ρ+β,ρ+ι,κ+μThe 14 ternary-phase regions are: α+δ+γ,δ+ν+γ,δ+μ+ν,δ+κ+μ,δ+ε+κ,ε+ζ+κ,ζ+η+κ,η+ι+κ,η+ρ+ι,ρ+β+χ,ρ+χ+η,η+β+χ,β+ρ+ι,κ+λ+μ. The existence of 10 binary compounds and 2 ternary compoundsat 500℃ has been confirmed in this work. They are Ti1Al, TiAl,TiAl2, TiAl3, DyAl3, DyAl2, DyAl, Dy3Al2, Dy2Al and Ti2Al20Dy,Ti4Al43Dy6 respectively. The maximum solid solubility of Ti in Dy2Al,Dy3Al2 and DyAl2is about 2.1at%, 3.6at%, 16.5at% and that of Dy inTi,Ti3Al and TiAl is less in 1at%.