Effect of forging processes on the microstructure and texture distribution of Ti-6Al-4V alloy

The mierostructure and texture evolution of Ti-6Al-4V alloy under different forging processes on a free forging hydraulic press were investigated by scanning electron microscopy, electron backscattered diffraction and X-ray diffraction. It is found that the microstructures of Ti-6Al-4V alloy under different forging modes, unidirectional forging and cross upsetting and stretching, are nearly the same. The distributions of ct phase and β phase in the difficult deformation zone, small deformation zone and large deformation zone are very similar, while the strain is distinctive in different forging regions. Further observations indicate that, in the edge region with small strain, the slip system is mainly the {0001} basal plane and forms the basal texture, {1120} and {1010} prismatic textures occur in the internal high strain region, while { 1122} and {1011} pyramidal textures appear in the place where the stress concentrates. The two forging processes can both improve the uniformity of deforming textures; in addition, cross upsetting and stretching is better than unidirectional forging.