Microstructures and textures evolution of Ta-7.5%W during annealing process

The organization and performance evolution of Ta-7.5%W at 1 050,1 200 and 1 360 ℃ were investigated by microstructure observation,transmission electron microscope(TEM) and hardness tests,and the texture evolution was investigated by orientation density function(ODF).It was found that after 1 360 ℃ annealing the hardness decreases rapidly from HV 300 to HV 240,and the recovery recrystallization occurs.Ta-7.5%W is anisotropic;the dislocation substructure appears in {111} orientation and the deformation zone appears in {100} orientation.The main textures of cold-rolled Ta-W alloy are {001},{112} and {110}.As the annealing temperature is 1 200 ℃,the recrystallization nucleation is mainly through the migration of the subgrain boundary and the growth of the subgrain in {111} orientation,while the recrystallization nucleation is mainly through the rotation and polymerization of the subgrain in {100} orientation;the texture of {001} increases and the texture of {112} decreases.While annealing at 1 360 ℃,the texture of {001} decreases rapidly,and the texture of {111} increases.