Microstructure and mechanical properties of pure Ti processed by high-ratio differential speed rolling at room temperature

High-strength Ti sheets could be fabricated by effective grain-refinement through high-ratio differential speed rolling for a thickness reduction of 63% in a single rolling pass at room temperature. Formation of narrowly spaced shear bands distributed uniformly over the entire thickness section of the sheet and a high temperature rise by intensive shear banding during rolling resulted in the formation of ultrafine grains with the size of 0.1–0.3 μm. The rolled Ti sheet exhibited an ultimate tensile strength of 895–915 MPa.