SHEAR BAND EVOLUTION AND NANOSTRUCTURE FORMATION IN TITANIUM BY COLD ROLLING

The microstructure evolution of the localized shear band in a cold-rolled commercial titanium was systematically investigated by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). A shear band with a width of approximately 25 μm was formed in the cold-rolled titanium and the microstructure inside the shear band was mainly nanograins with average size of 70 nm after 83% cold rolling reduction. TEM observations revealed that the grain refinement inside shear band was completely via a shear deformation-induced splitting and breaking-down of twin lamellae process.