Recrystallization Texture of Submicrocrystalline Niobium after Annealing

Resumo

Scanning electron microscopy shows that in pure niobium deformed by shear under pressure, a grain structure characterized by an axial texture of recrystallization is formed from the textureless deformed state during annealing. The sharpest texture is formed during annealing at 800°C. The fraction of the area occupied by recrystallized grains, in which planes (110) are parallel to the sample plane, reaches 90%; the fraction of high-angle boundaries (HABs) is 40%; and the average grain-boundary (misorientation) angle is 17°. The texture forms during selective growth of recrystallization centers. The formation of new recrystallization centers in addition to deformation-induced growing centers during 900°C annealing slightly increases the fraction of HABs, the average misorientation angle, and creates a blurred recrystallization texture.