Effect of cold rolling on microstructure and mechanical properties of CT20 titanium alloy

CT20 titanium alloy sheets with different thicknesses prepared by the rolling process were studied. Various techniques were used to characterize the microstructure, hardness and mechanical properties of the sheets in rolling direction(RD) and transverse direction(TD), and the intrinsic connection between microstructure and mechanical properties was analyzed. The results show that the high density of dislocations triggers the crystalline-to-amorphous transition during cold rolling. The increasing rolling reduction makes α phase elongate along RD, β phase and βt structure break severely. Massive dislocations and substructures introduced by cold rolling enhance the alloy hardness, raise the tensile strength and drop the elongation in RD and TD. The fracture type in RD is a ductile fracture, and that in TD is a mixed tough-brittle fracture. During the cold rolling process, the basal slip and prismatic slip are jointly involved in the evolution of the texture, and the resulting texture orientation has an essential influence on the slip behavior and mechanical properties of the sheets in RD and TD, while the different slip distances of dislocations in RD and TD lead to different work-hardening stages. © 2023 Central South University of Technology. All rights reserved.