Superplastic Deformation and Post Forming Tensile Properties of Ti-6Al-4V Sheet

摘要

Flow stress and strain rate sensitivity were measured for 6 batches of Ti-6Al-4V sheet of thickness 0.9 to 3.3 mm superplastically deformed in tension at 925 C at strain rates in the range 0.00002 to 0.004/sec. Room temperature tensile tests were carried out on material mill annealed (as-received), annealed at 925 C, and superplastically deformed at 925 C. Annealing at the forming temperature (925 C) reduces the 0.2% proof stress by 8% to 12%, and the tensile strength by 1% to 10% compared with mill annealed material. Superplastic true strain of 0.9 reduces the 0.2% proof stress and the tensile strength by a further 2%. Superplastic deformation reduces texture intensity in the alpha and beta phases, although the starting texture does not influence the superplastic deformation.