Effect of strain rate on dynamic softening behaviour and texture orientation of Ti55511 alloy deformed in single-phase region

Abstract

The influence of strain rate on dynamic softening and texture orientation of Ti55511 in the β single-phase region are investigated. Hot compression experiments were enforced at 880–920°C, strain rates of 0.001–1 s⁻¹ and the strain of 0.60. The continuous dynamic recrystallization mainly happens at 0.001–0.01 s⁻¹, which is generated by the progressive rotation of the subgrain orientation, and accompanied by discontinuous dynamic recrystallization that is generated by the strain induced boundary migration. DDRX grains with HAGB migration nucleation bulge are produced at higher strain rates of 0.1–1 s⁻¹. DRV is the main deformation mechanism. The DRX nucleation mechanism corresponding to different strain rates plays an important effect on the type and intensity of β texture. The {111}//Z texture consumed by recrystallized grains gradually transforms to {110}//Z and {100}//Z textures at a low strain rate, leading to the diminishment of {111}//Z texture strength slightly. Meanwhile, {110} <1-1x> and cube texture {100} <001> occur to transform with the increasing strain rate. The degree of plastic deformation of <111> and <110> grains is larger and the degree of CDRX is higher. The {110} <111> slip system can accelerate the drastic dislocation interaction to turn <111> soft orientation to <100> hard orientation.