时效过程中ω相辅助α相形核及α相对Ti-1300合金力学性能的影响

The microstructures of the aged samples after solution treatment with different aging treatments were observed and characterized by SEM, TEM and XRD. The effects of ω phase on the β→α phase transformation and microstructures on Ti-1300 alloy were also studied. The results show that the average size (length) of precipitated α phase is 54 nm after being heated at 350℃ for 10 min and then being heated at 500℃ for 4 h. The average size (length) of the α phase is 202 nm when the sample is directly held at 500℃ for 4 h. Only nanoscale ω phase were observed in the sample being heated to 350℃ at the rate of 4℃/min, while α phase nucleation attached to ω phase was observed in the sample which is heated to 400℃. When the sample is heated continuously to 500℃ and held for 4 h, ω phase disappeared and very fine uniform α precipitates are obtained in the microstructure. The hardening effect of α phase is stronger than that of ω phase.