Experimental Investigation of Phase Equilibria in the Ti—Al—Zr System at 1000–1300 °C

Abstract

Four partial isothermal sections of the Ti—Al—Zr system up to 60 at. % Al and 30 at. % Zr were experimentally established between 1000–1300 °C. Six heat-treated alloys were analysed by scanning electron microscopy, transmission electron microscopy, electron probe microanalysis, conventional and high-energy X-ray diffraction, and differential thermal analysis. Phase equilibria were determined between B2-ordered (β0), βTi,Zr, αTi, Ti3Al, TiAl, and ZrAl2.

Alloying Elements in Intermetallic γ‐TiAl Based Alloys – A Review on Their Influence on Phase Equilibria and Phase Transformations

“…In particular, Musi et al [ 228 ] reported that Zr stabilizes the γ phase at temperatures below this transition temperature, i.e., the amount of γ increases at the expense of α/α 2 . Additionally, the eutectoid temperature increases upon alloying with Zr, as demonstrated in Figure 12, indicating the stabilization of the α 2 compared to the α phase similar to the cases with Mo and V. [ 228,229 ] At intermediate temperatures, i.e., the temperature range of the α 2 + γ phase field region, sufficient alloying with Zr may cause the formation of the (Zr,Ti) 5 Al 3 phase. [ 225 ] With respect to ternary intermetallic compounds, contradicting results can be found for this system.…”

Advances in Zr-Based Alloys

“…Wen et al [37] investigated the oxidation behavior of FeCoNiCrMo high-entropy coatings by atmospheric plasma spraying on Zr-4 in steam at 1100 • C. A dense Cr 2 O 3 oxide layer was formed on the coating's surface after oxidation at 1100 • C, which grew from 1.5 to 3 µm after 15 to 60 min of oxidation, and the FeCoNiCrMo high-entropy coatings and the substrates diffused simultaneously, the FeCoNiCrMo high-entropy coating can effectively delay the oxidation of the Zr-4 substrate. Zahra et al [38] investigated the phase equilibria in the Ti-Al-Zr system at 1000-1300 • C via experimentation. The phase equilibria at all temperatures are different from the ones established before, i.e., B2-ordered β 0 already exists at 1000 • C and remains stable up to at least 1300 • C and only traces of Zr 5 Al 3 were observed.…”