Tensile behavior of orthorhombic alpha ''-titanium alloy studied by in situ X-ray diffraction

The tensile behavior of a Ti-11%Zr-14%Nb-10%Sn alloy with pure orthorhombic alpha '' phase was studied by in situ X-ray diffraction using synchrotron radiation. It is found that no phase transformation happens during the whole tensile process. The "double-yielding" platforms of this alloy are indeed due to a low stress yielding (similar to 400 MPa) followed with a significant work-hardening before necking and 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 alpha '' phase is largely improved to be over 900 MPa.