Superplastic response and associated microstructures in Ti-3AL-4V alloy at 800 degree

Ti-3AI-4V alloy was tested at 800 degree C by the method of cross head speed cycling. The alloy exhibited limited superplastic response at this temperature. Although strain rate sensitivity greater than 0.4 were observed but associated elongation was not large. The deformation behaviour may be attributed to slower diffusion rates in the beta phase as well as the less connected beta phase at this temperature. Strain induced softening was also observed at this temperature which may be attributed to the breakdown of initial banded microstructure into an equiaxed one. (author)