Phase equilibria of the Ti-Al-Nb system at 1300 °C

Phase equilibria in the Ti-Al-Nb system at 1300 °C were studied using X-ray diffraction, scanning electron microscopy and electron probe microanalysis. Using the results, an isothermal section at 1300 °C for this system was constructed. No ternary compound was observed in this work. The isothermal section is characterized by four three-phase regions (α + β + γ, β + γ + σ, σ + δ + β and σ +γ + ε) plus the corresponding two-phase regions. The locations and areas of the tie-triangles are different from the previous results. The homogeneity range of α, γ, σ, δ and ε is located along a constant Al concentration. - Highlights: • The isothermal section at 1300 °C in the Ti-Al-Nb system has been determined. • The isothermal section consists of 4 three-phase regions and 9 two-phase regions. • The β phase region expands and the σ and δ phases move to higher Al contents. • The single-phase regions α, γ, σ, δ and ε extend along the isoconcentrate of Al.