Abstrakt
High resolution scanning electron microscopy (SEM) is capable of imaging omega phase particles. The SEM observation of Ti15Mo metastable beta titanium alloy after ageing at 500 degrees C for 16 h revealed that the material contains coarse beta grains surrounded by grain boundary alpha phase.
Thin lamellae associated with alpha phase were observed in grains interior. Most importantly, small ellipsoidal particles with the size of similar to 100 nm were observed due to chemical contrast.
Sample for TEM observation was extracted using focused ion beam to prove that these particles belong to isothermal omega phase that evolves during annealing. In the addition, presence of different families of the omega phase in the material was observed by the combination of bright and dark field imaging.
Finally, thin lamellae of the alpha phase in the vicinity of grain boundary were observed using TEM.