Effects of strain state and slip mode on the texture evolution of a near-α TA15 titanium alloy during hot deformation based on crystal plasticity method

A thorough understanding of the texture evolution of near-a titanium alloys during the hot metal forming can help obtain an optimal crystallographic texture and material performance. The strain state has an obvious effect on the texture evolution of near-alpha titanium alloys during the hot metal forming. In this paper, the texture evolution of a near-alpha TA15 titanium alloy during the hot metal forming under different strain states were discussed based on the crystal plasticity finite element method. It is found that the basal and prismatic slip systems are regarded as the dominant slip modes due to the similar low critical resolved shear stress during the hot metal forming of the TA15 sheet rotating the lattice around the [10 (1) over bar0] and < 0001 > axis, respectively. Once both of them cannot be activated, the pyramidal-2 slipping occurs rotating the lattice around the [10 (1) over bar0] axis. The relationship between the texture evolution and strain state is established. All the (0001) orientations form a band perpendicular to the direction of the first principal strain. The width of the band along the direction of the second principal strain depends on the ratio of the compressive effect to the tensile effect of the second principal strain. This relationship can help control the crystallographic texture and mechanical properties of the titanium alloys component during the hot metal forming. (C) 2019 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.