Microstructure, texture evolution and mechanical behavior of Ti-3.5Al-5Mo-4V titanium alloy during hot rolling in a β field

Abstract

The microstructure, microtexture evolution, and corresponding mechanical behaviors of Ti-3.5Al-5Mo-4 V during hot rolling in the β field were investigated. The results showed that two distinct dynamic recrystallization (DRX) mechanisms exist during hot rolling, namely, continuous DRX (CDRX) with progressive rotation of sub-grains and discontinuous DRX (DDRX) comprising original grain boundary bulging and nucleation. Moreover, the texture evolution characterized by the orientation distribution function (ODF) suggests that the dominant textures are (001) < 110 > , (112) < 110 > , and (111) < 112 > textures owing to the occurrence of plane strain deformation and DRX. Furthermore, the expected balance between strength and plasticity was realized at a thickness reduction of 90% because of grain refinement and a reduction in dislocation density due to DRX. In addition, the increase in strength could also be attributed to the existence of (001) < 110 > and (112) < 110 > textures that were parallel to the tensile direction and perpendicular to the closely packed plane (110) of the β phase.