论文部分内容阅读
A new Ti2A1Nb-based alloy with the composition of Ti-22A1-25Nb-1Mo-IV-1Zr-0.2Si (at％) was fabricated in the sequence of arc melting,forging,solid solution and aging.Present paper focuses on the effects of aging temperatures (700,750,800,850 and 900 ℃) on microstructure,room-temperature tensile properties as well as tensile properties at 650 ℃ and creep properties at 650 ℃/150 MPa.It is obvious that the aging treatment promotes the precipitation of O lathes from B2 matrix.With aging temperature increasing,the content of O phase decreases and its size increases gradually,which leads to the decrease in tensile strengths both at room temperature and 650 ℃ and a little increase in ductility.For creep properties,the sample aged at 700 ℃ shows the best creep resistance due to its extremely high O phase content.Aging at 800 ℃ leads to the decrease in the content of O phase and softening of the alloy significantly.However,with aging temperature further increasing from 800 to 900 ℃,the precipitated O phase will be coarsened gradually,which strengthens the alloy again.