Manufacturing of ultrafine-grained titanium by caliber rolling in the laboratory and in industry

The mechanical properties and the microstructure of Grade 2 titanium semi-products processed by warm caliber rolling in both laboratory and industrial environments are studied. It is shown that this technology yields ultrafine-grained (UFG) microstructure with high tensile strength and good ductility at room temperature. Finite element modelling (FEM) suggests that the effectiveness of caliber rolling in grain refinement is mainly caused by the large, homogeneous imposed strain, similar to conventional severe plastic deformation (SPD) methods. It is proved that the mechanical and microstructural properties of titanium processed by the industrial equipment are similar to the characteristics of the material manufactured in the laboratory. This observation suggests that caliber rolling carried out in industrial environments may be a candidate technology in mass-production of UFG titanium with improved mechanical properties.