Transverse texture weakening and anisotropy improvement of Ti-6Al-4V alloy sheet via asymmetric rolling and static recrystallization annealing

Abstract

Traditional rolled titanium alloys usually exhibit a distinct transverse texture, which is quite stable in subsequent annealing and leads to anisotropic mechanical behaviors. In this work, Ti-6Al-4V alloy was fabricated by asymmetric rolling and recrystallization annealing. The microstructure, texture, and anisotropy evolution were systematically studied. The results show that the <0001>//ND ± 30° RD texture component is formed during the rolling thinning process under the combined action of compressive stress and shear stress. The corresponding grains and α_s prioritize nucleation and grow rapidly during subsequent annealing. The transverse texture are consumed or swallowed up before they grow up. The β phases provide secondary nucleation points for α grains. As a result, grains grown rapidly are decomposed and orientations are further established on adjacent matrix. The grains formed by preferential growth and secondary nucleation show more random orientation, and volume fraction of complete transverse texture decreases from 60.1% to 19.3%. Accordingly, the anisotropy of yield strength and tensile strength is decreased by 181 MPa and 195 MPa, respectively. The transverse texture is weakened by asymmetric rolling and static recrystallization, which provides an efficient way for producing high-performance rolled titanium alloy in the industry.