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.