Influence of Asymmetric Hot Rolling on Microstructure and Mechanical Property of Ti-6Al-4V Alloy Sheet

The experiments of asymmetric/symmetric hot rolling were carried out to investigate the effect of asymmetric hot rolling on the microstructure and the mechanical properties of titanium alloy. The metallographic microstructure, the mechanical property, the fracture morphology and the microscopic orientation of rolled samples were characterized. The results demonstrate that complex strain path is prior to monotonic strain path for refining grains and simultaneously improving the values of strength and ductility, and the grain sizes in asymmetrically rolled specimen surface are smaller than those in specimen center. Asymmetric hot rolling can refine grains more strongly compared with symmetric hot rolling. The values of strength and ductility of asymmetrically rolled specimens are higher than those of symmetrically rolled specimens, and the values of strength and ductility increase with the development of roll speed ratio. The plastic deformation mechanism of asymmetrically rolled specimen may be slip. While, the one of symmetrically rolled specimen may be twin or slip.