Abstract
In several titanium alloys the β phase, stable at high temperatures, can be retained on quenching. When re-heated at temperatures below 500°, the alloys become hard and brittle. This has been associated with the precipitation of an intermediate phase ω. To determine the structure of this ω phase, single crystal X-ray examination has been carried out on titanium-6 per cent iron alloy. The results obtained are as follows: (1) The ω structure has a complex body-centred cubic lattice and its lattice parameter is aω=9.76 Å. (2) The space group of ω structure is Im3m. (3) The orientation relationships between β phase and ω phase are (100)β\varparallel(100)ω, [010]β\varparallel[010]ω. (4) It is supposed that the ω phase may be an intermetallic compound but its situation on the equilibrium diagram is not clear.
