Analysis of Microstructure, Texture Evolution, and the Mechanism of Grain Refinement of Commercially Pure Titanium During Cold Rolling: Experiment and Simulation

A comprehensive understanding of the microstructures and texture evolutions during the rolling process is of great significance for the preparations of high-quality commercially pure titanium (CP-Ti) sheets. Therefore, in the present work, the effects of rolling reductions on the microstructures and textures of CP-Ti are investigated by optical microscope, electron backscatter diffraction, and X-ray diffraction. A crystal plasticity finite element model (CPFEM) is developed to accurately predict the rolling deformation behaviors of CP-Ti sheets. The results show that the slip and twinning including {11 (2) over bar2} < 11<(2)over bar>(3) over bar >, {11 (2) over bar4} < 22<(4)over bar>(3) over bar > compression twins and {10 (1) over bar2} < 10<(1)over bar>(1) over bar > extension twins are prone to plastic deformations during the whole rolling process. The c-axes of grains gradually tilt toward the transverse direction and the grains gradually deviate from the original < 10<(1)over bar>0 >//rolling direction (RD) to < 7<(2)over bar>(5) over bar0 >//RD. As a result, the mixed textures of {0001} < 10<(1)over bar>0 > and {0001} < 11<(2)over bar>0 > are developed in the specimen. The grain refinements are closely linked with the developments of {11 (2) over bar2} < 11<(2)over bar>(3) over bar > and {10 (1) over bar2} < 10<(1)over bar>(1) over bar > twins. In addition, the twin fractions and texture evolutions are well predicted by the CPFEM model. These results documented in this work should not only help to elucidate the microstructures and texture evolutions of CP-Ti, but also shed important light on improving its properties.