Enhancing the superplastic deformation capabilities of the Ti-6Al-4V alloy using superimposed oscillations

Abstract

This study investigates the effect of imposing low frequency, low amplitude oscillations during uniaxial tensile tests on the mechanical behaviour of the Ti-6Al-4V alloy under a typical superplastic temperature of 900 °C. Different material models were used to simulate these tests with the finite element software ABAQUS. A creep strain power model fit through an iterative FEA process yielded a high correlation to the force/displacement and thinning results from uniaxial tensile tests. The developed material models with and without oscillation materials were also used to simulate a free-bulge forming process within the strain rate range of 0.0003 to 0.01 s⁻¹ under constant strain rate testing. Within the domain of the parts formed in this study, the improvement in the forming time ranged from a 120 % reduction at elevated strain rates and reduced part complexity to 520 % in the most complex part geometry.