Effect of creep stress on the high-temperature tensile stability of TC11 titanium alloy

During high-temperature applications, tensile stability is significantly important and urgent for the security of components. In this paper, the high-temperature tensile tests under different creep strain were performed and analyzed through scanning electron microscope (SEM) and transmission electron microscope (TEM) of TC11 titanium alloy. It is found that the creep strain, dynamic α precipitation and deformation modes have significant influence on the high-temperature tensile behavior of TC11 titanium alloy. An abnormal characteristic of high-temperature tensile stress plateau was observed with the increasing of the creep strain. Moreover, an increment of 100 MPa for yield strength was achieved when the creep strain increased from 0.075 to 0.21%. For low creep strain, sample was controlled by the dislocation slip. While at high creep strain, it promotes the precipitation of nano-sized α particles, and dislocation slip hardly transfers across the α/β interface. Then, dislocation tangles, deformation twins and stacking faults become dominated, which results in an obvious stress plateau in the stress–strain curve.