Deformational behavior of face-centered cubic (FCC) phase in high-pure titanium

The deformation behavior of face-centered cubic (FCC) phase in annealed samples at room temperature was directly observed by Transmission electron microscope (TEM). It is found that FCC phase has excellent capacity of plastic deformation. Under cold-rolling, the FCC/HCP (hexagonal close-packed) phase interface slides and rotates, leading to deviation from the semi-coherent orientation relationship. The FCC phase has undergone various deformation modes such as shearing, bending, kinking and their combinations. With the increase of strain, the globularization of FCC phase is more remarkable, and bands are transformed into equiaxed grains. Kinking of FCC band structure under cold-rolling was first discovered in this work, which can lead to grain refinement and improve ductility. The globularization behavior of FCC phase is similar to that of α/β lamellar starting structure in titanium alloy at high temperature. This provides a new idea for the design of microstructure and properties of titanium and its alloys.