Microstructure And Texture Evolution During Cold Rolling And Annealing Of Commercially Pure Titanium Sheet

Commmercial pure titanium TA1 plate,which had been hot rolled and then annealed,with a classic bimodal distribution of basal poles was employed in the present thesis.The plate was cold rolled and annealed in the different temperature.EBSD techniques and X-ray diffraction were employed to research the microstructure and texture evolution during cold rolling and annealing.The plastic deformation mechanism,texture evolution and anisotropy during cold rolling and texture evolution during recrystallization annealing of CP-Ti were analyzed.The results can be summarized as follows:?1?For low to medium levels of deformation??40%?,the external strain was accomodated by slip and deformation twinnning,whereas slip predominated at higher reductions.?2?In the initial deformation stage,a large number of {1122}<1123> compressive twins and few {101₂}<101₁> tensile twins were activated.With increasing deformation,vast secondary {112₂}-{101₂} tensile twinning were activated inside compressive twins.?3?For the low deformation?<20%?,the cold-rolled texture was dominated by pyramid texture.As a result,CP-Ti sheet showed strong anisotropy.With the increasing deformation,the basal texture was produced on account of the activation of secondary twins.The pyramid texture and anisotropy gradually weaken.When the deformation is reached to 40%,the strength of basal texture is strongest and the CP-Ti sheet showed strong isotropy.With the further increase of the deformation,the basal texture gradually disappeared and the main texture components were pyramid texture,resulting ina stronger anisotropy.?4?With increase in annealing time,recrystallized grains were increasing and the quantity of twins decreased.The speed of recrystallization annealing increased with the increase of annealing temperature and deformation reduction.?5?The basal texture was inherited from the cold-rolled plate with 40% reduction after recrystallization annealing.With increase in annealing time,the strength of basal texture was increased.The main texture components were pyramid texture after annealing for 20% and 85% reduction samples.?6?With increase in annealing temperature and time,some cold-rolled texture gradually disappeared and new recrystallization textureformed and gradually strengthened.