Experimental study and superplastic rheological characterization of Ti-6Al-4V

Abstract

The superplastic behaviour of a titanium alloy base Ti-6Al-4V during biaxial test was investigated. A numerical model using a finite element method is proposed to examine the superplastic deformation behaviour of an appropriate axisymmetric shaped part. An experimental procedure based on the measurement of the pressure applied and the height of the dome apex of the formed part, is used to identify the rheological parameters of the material behaviour law. This identification was carried out by comparisons between the results of simulation and experimentation relating to thickness, equivalent strain and stress. Three inflation tests were carried out at different equivalent strain rates (4 × 10 −4 , 6 × 10 −4 and 8 × 10 −4 s −1). This procedure is applied successfully to the forming of an industrial part. Indeed, this study henceforth allows one to predict thickness evolution in any point of an industrial part for an optimization of its uniformity.