Abstract:Ti-600 is one of the high performance titanium alloys used at 600 ℃, which was developed in Northwest Institute for Nonferrous Metal Research (NIN) in China. The tensile and creep properties of Ti-600 alloy with different thermal treatment conditions were investigated. The results indicate that Ti-600 alloy possesses favorite comprehensive properties solution-treated at  1 020 ℃ for 1 h, then air-cool, and aged at 650 ℃ for 8 h, finally air-cooling, especially possesses quite good creep resistance. The residual deformation is less than 0.1% for the alloy exposed at 600 ℃ for 100 h with the stress of 150 MPa, and the bimodal microstructures of the alloy are almost the same as that of the alloy treated by duplex thermal treatment, only needle primary a phases became relatively thicker and coarsened. The ultimate strength and the elongation of the alloy tested at ambient temperature are 1 080 MPa and 12%, respectively; while at 600 ℃, they are 690 MPa and 16%, respectively. The ductility of the alloy tested at room, temperature is no less than 5% after thermal exposing at 600 ℃ for 100 h.

Key words: Ti-600 alloy; high temperature titanium alloy; tensile property; creep resistance