Effect of yttrium on mechanical properties, thermal stability and creep resistance of high temperature titanium alloy Ti-1100

The tensile properties before and after exposed at 600 °C for 100 h and creep strain at the condition of 600 °C/150 MPa/100 h were measured for Ti-1100 and Ti-1100 with 0.1%(mass fraction) yttrium, respectively. The microstructures of unexposed and thermally exposed specimens were studied by optical microscopy and transmission electron microscopy. The addition of 0.1% Y to Ti-1100 is beneficial to the improvement of tensile ductility, thermal stability and creep property of the alloy, which is related to the microstructural changes, precipitated phases (α₂ phase and silicide) and dislocation structures resulted from the presence of Y₂O₃ oxide.