Tensile behavior of orthorhombic α″-titanium alloy studied by in situ X-ray diffraction

To our knowledge, the tensile behavior of single orthorhombic α″ phase was not reported previously. Here we studied a Ti-11%Zr-14%Nb-10%Sn alloy by in situ synchrotron radiation x-ray diffraction. It is found that the alloy only contains α″ phase and no phase transformation happens during the whole tensile process. The “double-yielding” platforms of this alloy are indeed due to a low stress (∼ 400 MPa) yielding followed with a significant work-hardening before necking fracture. In this process, the [0 2 2] orientation of grains more approaches the tensile direction and the [2 0 0] moves to the transverse, causing the lattice parameter a to be shrunk, and b and c elongated, and the formation of texture. The similar texture can also be produced upon cold rolling by which the yield strength of the α″ phase is largely improved to be over 900 MPa.