Characteristics of microstructures and second-phase particles in Y-bearing Ti-1100 alloy

The characteristics of microstructures and second-phase particles in yttrium (0.1 mass%) bearing Ti-1100 high temperature titanium alloy were investigated at different conditions. The results show that the prior β grain and α platelets in Ti-1100 alloy with yttrium are remarkably refined compared to Ti-1100 alloy without yttrium, and that the coarsening rate of the refined microstructure in Ti-1100 alloy with yttrium is slow at higher annealing temperature and slower cooling rate. The reason is attributed to the formation of small size and stable Y₂O₃ particles which delays the coarsening of the microstructure. The special precipitation features of silicide and α₂ phase in yttrium-bearing Ti-1100 alloy are also discussed.