Table 1.
Equilibrium invariant reactions according to the current knowledge of the equilibrium phase diagram29,50 for the Ti-2wt.% La alloy (Ti-2La) contrasted with the transformations identified in situ (Fig. 4), using high-energy synchrotron X-ray diffraction (HEXRD) during cooling from 950 °C (L1 + β field) with 20 °C min−1
| Phase diagram | In situ HEXRD | ||
|---|---|---|---|
| Invariant reaction | Temperature (°C) | Suggested transformation | Temperature range (°C) |
| – | – | Peritectic L1 + β → α | 950–900 |
| – | – | Allotropic β → α | 900–850 |
| Peritectic L1 + β ↔ La-bcc | 922 | Peritectic L1 + β → La-bcc | 875–850 |
| Peritectoid La-bcc + β ↔ α | 887 | – | – |
| Eutectoid La-bcc ↔ La-fcc + α | 857 | Eutectoid La-bcc → La-fcc + α | 850–700 |
| Allotropic La-fcc ↔ La-dhcp | 277 | – | – |