Deformation of a Ti-Nb alloy containing α"-martensite and omega phases

Microscopic deformation of a Ti-17at. %Nb alloy with high fractions of α″-martensite and ω phases was studied by in-situ synchrotron X-ray diffraction. Textures, phase fractions, individual lattice strains, and peak intensities during deformation were studied. It is found that, to accommodate the external tensile strain, some of the α″ and ω grains were first transformed to the β-phase, which then continuously transformed to the α″-phase with chosen variants that effectively accommodate the deformation strain. A strong (010)_α″ fiber texture was formed at the expense of the (001)_α″ and (111)_α″ fiber textures. Above 400 MPa applied stress, (110)_α″ deformation twinning was triggered with a simultaneous stress relaxation in the (110)_α″ family and a slight increase in its texture strength in the loading direction.